Geysir Geothermal Area

The Geysir Geothermal Area is a small but world-famous geothermal field in the Haukadalur valley of southwestern Iceland, in the country's South region and a key stop on the popular "Golden Circle" tourist route about 100 kilometers (60 miles) east of Reykjavík. Covering roughly 3 square kilometers (1.2 square miles), it was given formal protection as a natural monument in 2020 ^[1]. The field is set on the slopes of the Laugarfjall rise beside the Hvítá river and contains around thirty hot springs, geysers, fumaroles, and mud pools.

Its centerpiece is the Great Geysir, the spouting hot spring that gave its name to geysers everywhere — the word "geyser" derives from the Icelandic verb "geysa," meaning "to gush." Geysir has been documented since at least the late 13th century and once erupted spectacularly, hurling boiling water to heights of 60 meters or more (a column of about 170 meters / 560 feet was recorded in 1845), but it has been largely dormant for the past century, erupting only rarely after earthquakes ^[1]. Today the reliable performer is the neighboring Strokkur ("the churn"), which erupts every few minutes — typically every 6 to 10 minutes — sending a column of water 15 to 20 meters (and occasionally up to 40 meters) into the air.

Beyond the two famous geysers, the field's many features include the colorful Konungshver ("the King's Spring"), the small Litli Geysir, and the deep blue pool of Blesi. One of Iceland's most visited natural attractions, the Geysir area showcases the island's intense geothermal activity in a compact, easily accessible setting.

The Geysir geothermal field is, by any conventional measure of fauna, a sparse environment. Scalding ground, mineral-laden water, and the constant discharge of steam create conditions that exclude most animals from the active hot-spring zone itself. Yet this apparent emptiness conceals a genuinely remarkable biological dimension: the warm waters and runoff channels of the field host communities of thermophilic microorganisms that have attracted sustained scientific interest and represent the most distinctive wildlife the site can claim. The broader Haukadalur valley surrounding the field, and the Hvítá river flowing nearby, do support a characteristic assemblage of Icelandic birds and fish — modest in numbers and entirely typical of the subarctic south, but worth knowing before a visit. ^[1]

The living signatures of the geothermal field are the microbial mats that coat rocks and line the outflow channels wherever hot water spills away from the springs and cools along a temperature gradient. Thermophilic bacteria and archaea colonise these channels in temperature-sorted zones: where the runoff is hottest, strictly heat-loving archaea and hydrogen-oxidising bacteria dominate, thriving above 70 °C (158 °F) and metabolising hydrogen and sulphur compounds rather than light. As the water cools to roughly 50–65 °C (122–149 °F) the community shifts to include filamentous bacteria alongside photosynthetic cyanobacteria, and below about 50 °C (122 °F) the cyanobacteria become dominant, harvesting sunlight through the same fundamental biochemistry as land plants. Research on Icelandic alkaline hot springs — conditions comparable to those at Geysir — has found these phototrophic mats characterised by various cyanobacteria, with heat-loving bacteria prominent at the higher temperatures. Studies of multiple Icelandic sites have found that around 56 percent of the microbial genetic variants detected occur only in Iceland, suggesting that local geothermal pools harbour lineages that have evolved in relative isolation. ^[2]

The visual result of this microbial stratification is the colour banding that gives the outflow channels and pool margins their distinctive look: yellow-green where photosynthetic organisms are active, shading through orange and red where different chemolithotrophic bacteria metabolise iron and sulphur, and near-white or colourless at the coolest fringes where the thermal advantage disappears. The blue of the pools themselves, famously vivid in features such as Blesi, is a physical rather than biological effect — deep, mineral-rich geothermal water scatters short wavelengths of light — but the surrounding colour palette of oranges and greens is largely microbial in origin. Visitors walking the field are observing, in the coloured rinds around every hot spring, ecosystems that have no equivalent in temperate nature and that function within temperature ranges lethal to virtually all multicellular life on Earth. Iceland's geothermal sites have been studied precisely because they are considered analogues for early-Earth conditions and for the potential habitability of thermally active bodies elsewhere in the solar system. ^[3]

Bird life at the Geysir field itself is opportunistic rather than resident. Common ravens, among the most adaptable birds in Iceland, range widely across the interior and are regularly seen over visitor areas, drawn by the food waste that inevitably accumulates near the car park and hotel. Arctic terns and various large gulls — black-headed and great black-backed gulls among them — move through the valley on foraging flights from lowland wetlands. The broader Haukadalur valley, with its patches of heath, wet grassland, and rough pasture, is far more productive for birdwatching than the active geothermal zone. Golden plovers, the unofficial harbingers of the Icelandic spring whose first sighting each March-April is a noted cultural event, breed in open grassy areas throughout the south including this region. Common snipe drum over wet meadows, and both whimbrel and redshank — long-legged waders that nest in flat moorland — are present in summer across south Iceland's lowlands. The meadow pipit is typically the most abundant small bird of the heath, occupying the grassy margins in numbers that make it a near-constant presence. ^[4]

Whooper swans, Iceland's only breeding swan and a species that has nested across the island since before recorded history, use the shallow wetlands and river margins of the south on both breeding territories and staging areas during spring and autumn movement. The Hvítá river, which runs past the Haukadalur valley a short distance from the geothermal field, provides habitat for the three freshwater fish species that define Icelandic angling: Atlantic salmon, brown trout, and Arctic char. The Hvítá is rated among the better salmon rivers in Iceland, its fish congregating particularly where tributaries enter the main channel, and brown trout and char are present throughout the system. Rock ptarmigan, the only grouse native to Iceland, inhabit higher and more vegetated ground above the valley floor; they remain year-round, shifting to white winter plumage and descending slightly in elevation when snow covers the uplands. ^[5]

The Arctic fox holds a singular distinction in Iceland as the only land mammal native to the island, having arrived during the last ice age when sea ice connected Iceland to northern landmasses. Its present population is estimated at around 8,000 to 10,000 individuals distributed from coastal cliffs to highland interiors, with the Westfjords the primary stronghold for the species. The species is wide-ranging and individuals move through highland areas including the general region of the south interior, though sightings near the Geysir visitor complex are uncommon given the level of human traffic. Iceland has no native land reptiles or amphibians — the island's isolation and climate have excluded them entirely — and its mammal fauna otherwise consists of introduced species such as reindeer (confined to the east), escaped mink and brown rat, and marine mammals such as seals along the coast. The geothermal field thus presents an honest ecological picture: extraordinary at the microbial scale, unremarkable for large animals, and representative of the wider subarctic fauna of southern Iceland's interior once visitors step back from the springs themselves. ^[6]

The vegetation of the Geysir geothermal field reflects the stark contrast between ground hostile to most plant life and the broader grassland and heath of the Haukadalur valley. The geothermal field itself covers roughly 3 square kilometres (1.2 square miles) and thermal surveys have identified around 364 distinct hot areas within it, according to Wikipedia's account of the Geysir system ^[1]. Where water temperatures are highest and silica-rich discharge continually wets the surface, the ground is encrusted with geyserite — a form of opaline siliceous sinter that precipitates as mineral-laden water evaporates. These pale, porcelain-like terraces and mounds around the active vents are largely barren of vascular plants. Hot, acidic or alkaline soils, scalding splash zones, and the constant deposition of minerals make permanent root establishment impossible for grasses or shrubs in the innermost zones.

Even in the harshest geothermal environments, microscopic life takes hold. In Icelandic hot springs, cyanobacteria and algae form colourful biological mats along the outflow channels and edges of warm pools wherever temperatures fall to survivable levels. Research on thermophilic cyanobacteria from Iceland's geothermal springs has documented organisms that thrive at temperatures between approximately 43 and 65 degrees Celsius (109 to 149 degrees Fahrenheit), forming loose, weakly encrusted green, orange, and red mats depending on temperature and chemistry ^[2]. These pigmented mats are among the most visible signs of life in and immediately around the geothermal channels, coating rocks and mineral surfaces with thin biological films that give many of Geysir's pools their vivid colouring. As outflow water cools with distance from the vent, the diversity of these communities increases and mosses begin to colonise the margins where conditions are less extreme.

Away from the active thermal features, the soils of the Haukadalur valley support vegetation typical of Icelandic lowland heath and grassland. Iceland's heathlands are dominated by low-growing dwarf shrubs, and the commonest include black crowberry, bog bilberry, and common heather, which together form a dense, mat-forming layer across well-drained slopes and hillsides ^[3]. Dwarf birch, several willow species including arctic willow and tea-leaved willow, and creeping juniper contribute to the shrub layer in sheltered areas, rarely growing more than knee-height in the exposed valley setting. Mosses and lichens carpet the ground between shrubs, and in wetter hollows and drainage channels, sedges including common cottongrass and lyngbye's sedge form dense tussocky stands. Wildflowers add seasonal colour: alpine bartsia, wild thyme, and alpine bistort bloom through the brief summer, and the insectivorous common butterwort can be found in damp, nutrient-poor patches.

One locally notable ecological feature is the mild warming effect that diffuse geothermal heat exerts on soils at the margins of the active field. Warm ground slightly extends the growing season and can promote denser or earlier grass and herb growth compared with unheated soils a short distance away. The iceland-nh.net vegetation resource notes that certain species with a thermal soil preference — including marsh cudweed, marsh pennywort, and drug eyebright — are associated with geothermally influenced ground in Iceland ^[3]. These warmth-associated plants represent a subtle botanical signature of the geothermal influence extending beyond the bare sinter terraces, blurring the boundary between the lifeless mineral zone and the living heath.

A short distance from the geothermal field, the Haukadalsskogur woodland stands as one of the most significant afforestation achievements in South Iceland. The forest's origins date to 1938, when a Danish benefactor purchased part of the Haukadalur valley and put measures in place to halt severe soil erosion; upon his death two years later he bequeathed approximately 1,600 hectares (3,950 acres) of land to Skógrækt ríkisins, the Icelandic Forest Service, which continued and expanded the planting programme ^[4]. Haukadalsskogur is now described as the most extensively planted of all Iceland's national forests. The woodland contains a mixture of native downy birch and a range of introduced conifers; Sitka spruce and black cottonwood from Alaska have proved particularly productive in the valley's moist, fertile soils, with the most vigorous stands exceeding ten cubic metres of growth per hectare per year ^[5]. Siberian larch, Norway spruce, lodgepole pine, and smaller numbers of subalpine fir and hemlock round out the species palette, creating a varied canopy quite unlike anything in the surrounding open landscape.

The contrast between Haukadalsskogur and the geothermal field just a short drive away illustrates the full range of the valley's plant life. The geothermal field presents a near-lunar surface of pale geyserite, steaming vents, and vivid algal mats where only the most heat-tolerant microorganisms can persist. The open valley heath beyond its margins supports the crowberry, bilberry, and moss communities typical of lowland Iceland. And the mature woodland of Haukadalsskogur, growing on land that a century ago was eroded and degraded, demonstrates how significantly Iceland's afforestation programme has transformed formerly bare hillsides into shaded, multi-layered forest habitat ^[6]. Together these three zones — bare geothermal sinter, open heath, and planted forest — make the Haukadalur valley an unusually compressed example of Iceland's wider landscape contrasts.

The Geysir Geothermal Area sits at the intersection of two of Earth's most powerful geological forces. Iceland straddles the Mid-Atlantic Ridge, the diverging boundary between the Eurasian and North American tectonic plates, and simultaneously lies above a deep mantle plume that drives exceptional volcanism across the island. Together these forces produce roughly 200 high-temperature geothermal systems, all confined to active volcanic rift zones where heat from shallow igneous intrusions keeps crustal temperatures anomalously high. The Haukadalur field in the West Volcanic Zone belongs to this category, drawing its energy not from current eruptions but from residual heat within a volcanic complex whose surface lavas last erupted more than 10,000 years ago. ^[1] That the landscape above is quiet while the ground below seethes at extreme temperatures is one of the defining paradoxes of Icelandic geology.

The field stretches across approximately 3 square kilometres (1.2 sq mi) on the eastern slopes of Laugarfjall, a rhyolitic lava dome rising 187 metres (614 ft) above the valley floor. Rhyolite is a silica-rich volcanic rock, and its presence here is significant on two counts. It signals a more evolved and sustained heat source at depth than the simple basaltic intrusions common elsewhere in Iceland, and its high silica content means groundwater circulating through it dissolves large quantities of silicon dioxide that later precipitates as geyserite at the surface. The hyaloclastite rock underlying parts of the field, glassy volcanic material shattered during subglacial eruptions, also contributes a dense fracture network that channels water through the subsurface plumbing. ^[2] Detailed thermal mapping across the valley has identified 364 distinct hot areas, and the visible field hosts approximately 30 named hot springs, fumaroles, and mud pools.

The eruption mechanism depends on an interplay of pressure, geometry, and phase change. Groundwater, sourced in part from the southern margin of the Langjokull ice sheet roughly 50 kilometres (31 mi) to the north, percolates downward through volcanic rock fractures and is heated by contact with hot rock at depth. The critical physics lies in the fact that water under pressure has a boiling point well above 100 degrees Celsius (212 degrees Fahrenheit): the weight of the overlying water column suppresses boiling even as deeper temperatures approach or exceed that threshold. The Great Geysir's funnel-shaped conduit narrows from 0.4 to 1.0 metres (1.3 to 3.3 ft) at the surface down to a constricted channel at roughly 23 metres (75 ft) depth, with several branches and cavities below 16 metres (52 ft). Upper conduit temperatures reach 85 to 95 degrees Celsius (185 to 203 degrees Fahrenheit) while deeper zones approach approximately 120 degrees Celsius (248 degrees Fahrenheit). ^[1] When water near the top of the conduit spills over the rim, the sudden pressure reduction triggers a chain reaction: the superheated water below explosively flashes to steam and blasts the entire column skyward in seconds. The system then refills, reheats, and repeats.

Strokkur, approximately 50 metres (160 ft) south of the Great Geysir, provides the field's most reliable demonstration of this process. Its conduit incorporates a bubble trap, a lateral cavity where steam accumulates during the refilling phase. Research has identified four distinct phases in each eruptive cycle: the eruption itself, post-eruptive conduit refilling, gas accumulation within the bubble trap, and collapse of steam bubbles at shallow depth that triggers the next eruption. ^[3] The cycle repeats every 6 to 10 minutes, launching a column of boiling water and steam 15 to 20 metres (49 to 66 ft) high, with exceptional bursts reaching 40 metres (130 ft). Strokkur's unusual regularity among the world's geysers reflects the precise geometry of this bubble trap combined with steady heat flux from below.

The Great Geysir operates at a grander scale but far less predictably. Hot springs have existed at this location for approximately 10,000 years, yet dating of the siliceous sinter apron around the vent has narrowed the formation of the geyser itself to around 1150 CE. ^[1] The earliest written record dates to 1294, when a major earthquake appears to have opened the conduit network and triggered vigorous new activity. At historical peaks, eruptions reached extraordinary heights: Robert Bunsen recorded columns of 45 to 54 metres (148 to 177 ft) in 1846, while observations from 1845 documented an eruption reaching 170 metres (558 ft), among the tallest geyser eruptions ever recorded. Geysir entered extended near-dormancy before 1896, ceased almost entirely around 1916, and now erupts rarely and only following seismic disturbance.

The system's sensitivity to earthquakes is one of its most striking properties. Geyser plumbing depends on precisely sized conduits and constrictions, so even moderate shaking can seal old fractures, open new ones, or alter the bubble-trap geometry governing eruption rhythm. The 1294 earthquake initiated Geysir's first documented active period. Seismic events in 1789 unblocked Strokkur's conduit, giving that geyser its first recorded eruptions. In 1896 another earthquake revived the Great Geysir to multiple eruptions daily. Most dramatically, magnitude 6.5 earthquakes in June 2000 reactivated the dormant Great Geysir so forcefully that it erupted to 122 metres (400 ft) for two days before subsiding again. ^[4] Human interventions have demonstrated the same hydraulic sensitivity: lowering the water table via drainage channels and adding soap to the basin have both been used historically to trigger eruptions on demand, showing that the threshold between pressurized dormancy and violent eruption requires only a small perturbation.

The most visible record of the field's long hydrothermal history lies in the geyserite, or siliceous sinter, that crusts the ground around every vent. As silica-laden geothermal water erupts and cools, dissolved silicon dioxide precipitates as opaline silica, building up into pale grey and white crusts, mounds, terraces, and scalloped rims over centuries. ^[5] Geyserite forms only where discharge temperatures exceed roughly 75 degrees Celsius (167 degrees Fahrenheit), so its distribution precisely maps the hottest zones across the field. The sinter apron around the Great Geysir is thick enough that researchers have used stratigraphic dating of its layers to establish the 1150 CE formation date and to identify past dormancy periods where deposition halted. Elsewhere in the field, iron oxides stain cooler outflow channels rust-brown and orange, sulfur compounds create yellow deposits around fumaroles, and dense thermophilic algae add vivid blue-green and orange hues to spring margins, together composing a mineral and biological record written directly in the rock and water of the valley floor. ^[6]

The Geysir Geothermal Area sits in the Haukadalur valley of southern Iceland at roughly 100-120 metres (330-395 ft) above sea level, about 115 kilometres (71 miles) east-northeast of Reykjavík. The climate belongs to the subpolar oceanic type, classified as Cfc in the Köppen-Geiger system, a classification that applies to much of Iceland's southern and southwestern lowlands ^[1]. This regime is defined by cool summers in which the warmest months rarely exceed 22 °C (72 °F), mild winters relative to the high latitude, and precipitation spread throughout the year. The moderating force is the North Atlantic Current, an extension of the Gulf Stream that keeps temperatures far above what latitudes near 64 °N would otherwise produce. Because Haukadalur lies inland yet still within the broad southern lowlands, it sits somewhat beyond the immediate oceanic influence of Reykjavík's harbour: frosts arrive earlier in autumn, depart later in spring, and snow cover is more persistent through winter. The result is a climate that feels genuinely cold for much of the year but rarely produces the extreme cold found in Iceland's interior highlands ^[2].

Temperatures at Geysir broadly follow the pattern recorded at nearby southern Iceland stations, with the coastal station at Reykjavík providing the most complete reference data. The Reykjavík record shows a mean annual temperature of about 4.4 °C (40 °F), a July average near 11-12 °C (52-54 °F), and a January average near -0.6 °C (31 °F) ^[3]. Climate data for the Haukadalur locality suggests daytime highs in July averaging around 15 °C (59 °F) and overnight lows near 8 °C (46 °F), while February daytime highs hover around 1 °C (34 °F) with nights falling to -5 °C (23 °F) or lower — figures from the weather-and-climate.com Haukadalur dataset ^[4]. Occasional warm spells push temperatures above 20 °C (68 °F) in midsummer, though such warmth is brief and uncommon. Ground frost is common from October through April, and the open site offers little shelter: wind chill regularly makes the air feel significantly colder than the thermometer suggests ^[5].

Precipitation is frequent and falls in every month of the year, with a pronounced maximum in late autumn and winter. The Haukadalur climate record shows an annual total of approximately 1,840 mm (72 in), substantially wetter than Reykjavík's coastal station at around 876 mm (34.5 in) per year, reflecting the valley's position where moist Atlantic air releases moisture as it moves inland ^[4]. February is the wettest month at roughly 204 mm (8 in), while June is the driest at around 100 mm (3.9 in) — still wet by most global standards. Rain and drizzle dominate from late spring through early autumn; from October onward precipitation increasingly falls as snow or sleet. Snowfall in the Reykjavík area averages around 102 cm (40 in) annually, and the inland elevation around Geysir ensures somewhat heavier accumulations and longer-lasting cover ^[1]. Sudden shifts between sun, cloud, rain, and wind within a single afternoon are the norm, and layered, waterproof clothing is essential on every visit ^[6].

Wind is among the most defining elements of the Geysir experience. Iceland lies in a zone of vigorous Atlantic low-pressure systems that drive persistent westerly and south-westerly winds across the island. Lowland areas of the south experience gusts reaching 18 metres per second (65 km/h) on ten to twenty days per year, and the open, treeless landscape around Haukadalur offers no windbreak ^[1]. The Icelandic language reflects this reality with over 150 distinct words for different wind conditions, from logn (dead calm) to fárviðri (storm) ^[5]. At the site itself, strong wind can bend Strokkur's eruption column sideways immediately after it clears the vent, and visitors are advised to position themselves upwind to avoid wind-driven droplets. Hats, camera straps, and loose gear should be secured as a matter of course.

The seasonal swing in daylight at latitude 64 °N is among the most dramatic at any well-visited European tourist site. Around the summer solstice, the Haukadalur valley receives approximately 21 hours and 8 minutes of daylight; the sun dips briefly below the horizon at midnight but it never grows fully dark — the near-midnight-sun period that makes evening visits to Geysir entirely practical ^[7]. By the winter solstice, daylight shrinks to roughly 4 hours and 7 minutes, with sunrise around 11:30 and sunset by 15:30. Tour operators time Golden Circle itineraries so that Geysir is reached during the brightest central hours of the day. Those short winter days carry a compensation: long, dark nights give Iceland some of its best aurora borealis conditions. The country sits beneath the northern auroral oval, and the season for northern lights runs from late August through mid-April, with the equinox months of September-October and March-April regarded as particularly productive ^[8]. The dark, open valley around Geysir, far from significant artificial light, is a practical viewing location on clear nights.

The geothermal character of the site transforms visibly with the seasons and creates its own microclimate. In cold weather, the contrast between boiling vent water and frigid ambient air causes steam to condense into far denser, more dramatic plumes than in summer warmth ^[9]. On a frosty January morning the entire field exhales a thick white haze that hangs across the valley floor; hot springs and mud pots that attract little attention on a warm July afternoon become towering ghostly columns in midwinter. A practical consequence of geothermal heat is that the ground immediately around active vents stays unfrozen and often snow-free even when surrounding meadows are deep in winter white, creating a striking visual contrast of steaming bare earth ringed by snow ^[10]. The site is open year-round: summer draws the largest crowds under the midnight sun; winter attracts photographers and aurora-seekers willing to trade short daylight for snow scenery, dramatic steam, and clear dark skies. Spring and autumn offer smaller crowds but rapid weather swings between wintry squalls and clear golden light. In every season, wind-proof and waterproof outer layers, grip-soled footwear for icy boardwalks, and flexibility around fast-changing conditions are the standing requirements for a visit to Haukadalur ^[11].

The valley of Haukadalur has been inhabited and culturally significant since Iceland's earliest centuries of settlement. The district gave its name to the Haukdælir clan, one of the most influential medieval Icelandic families, and the farm and church at Haukadalur functioned as a seat of learning in the south of the island from early Christian times. Around 1101, the historian Ari Þorgilsson — known as Ari the Wise and celebrated as the first person to write history in Old Norse — received his education here under Teitur Ísleifsson, son of Iceland's first bishop. ^[1] That a school of such consequence sat within sight of the geothermal field speaks to the long interweaving of human settlement and volcanic landscape in this part of south Iceland. The hot springs were almost certainly known to settlers from the ninth and tenth centuries onward, providing reliable warmth in an otherwise demanding environment.

The modern documentary history of the geysers begins with the great earthquakes of 1294, recorded in the Icelandic chronicle Oddaverjaannáll. Those seismic events reshaped the geothermal field dramatically, deepening fractures and bringing previously dormant vents to violent new life, and it is from 1294 that the erupting spring later known as Geysir is first unambiguously described. ^[2] The catastrophic reordering of the landscape that year established the configuration of the Haukadalur field broadly recognisable to later visitors. Activity fluctuated considerably over the following centuries, driven by shifting seismic stresses and groundwater conditions, and the written record remained sparse until the seventeenth century. The name Geysir appears in written sources for the first time in 1647, recorded by Bishop Brynjólfur Sveinsson. The word derives from the Icelandic verb geysa, meaning "to gush" or "to rush forth," rooted in Old Norse and traceable to a Proto-Germanic root meaning to pour. ^[3] From this single place name the entire modern scientific and linguistic category was born: as European travellers carried accounts of the erupting spring back to the wider world, the proper noun became a common noun. "Geyser" entered English — and from English spread into most other European languages — as the universal term for any periodically erupting hot spring. ^[4] Old Faithful at Yellowstone, Castle Geyser, and spouting springs in New Zealand, Russia, and Chile all owe their generic classification to this one Icelandic spring. Geysir is the eponym for its entire geological category.

By the early nineteenth century the spring had drawn natural philosophers from across Europe. The British geologist George Mackenzie visited in 1810 and proposed a preliminary steam-expansion theory. ^[2] The decisive investigation came in 1846, when the German chemist Robert Bunsen travelled to Iceland on an expedition sponsored by King Christian VIII of Denmark. Bunsen lowered thermometers into Geysir's vent to make the first systematic pressure and temperature measurements ever taken inside an erupting spring, finding that water temperature increased with depth and that the column was superheated relative to the boiling point at surface pressure. He published his findings in 1847 in Physikalische Beobachtungen über die hauptsächliche Geysir Islands, proposing that eruptions begin when boiling initiates at the top of the column, releasing pressure and triggering a chain reaction of flashing steam that propagates downward through the superheated water. ^[5] Bunsen measured eruption heights of 45 to 54 metres (148 to 177 feet), providing the first quantitative record of Geysir's power. Modern geothermal science has confirmed the fundamental logic of his theory, making the 1846–47 fieldwork one of the foundational moments in volcanology. ^[2]

The most celebrated royal association with the site dates to 1874, when King Christian IX of Denmark — constitutionally also King of Iceland — made the arduous journey for the millennial celebration of Iceland's settlement, the first time a reigning monarch had visited in person. A visit to Haukadalur formed part of the royal itinerary, and a pool in the geothermal field was subsequently named Konungshver, meaning "the King's Spring," to commemorate the occasion. ^[6] The spring bearing that name appeared only in 1896 following a major earthquake, named retrospectively in Christian IX's honour. Later royal visits left carved stone markers on the hill above Konungshver bearing the initials of King Frederik VIII (1907) and King Christian X (1921). ^[7]

Until the late nineteenth century the Geysir field remained in the hands of local farming families. That changed in 1894, when an Irish visitor named James Craig — later elevated to the peerage as Lord Craigavon and destined to become the first Prime Minister of Northern Ireland — purchased the land from the Haukadalur farmers Sigurður Pálsson, Jón Sigurðsson, and Greipur Sigurðsson for 3,000 Danish krónur. ^[8] Craig had encountered the struggling farmers during a visit the previous summer, found the Icelandic government unwilling to buy, and stepped in himself. He erected fences around the site and charged visitors an entrance fee. He subsequently transferred ownership to a friend, E. Rogers, who had never visited Iceland, had no particular interest in the property, and dropped the charges. The episode introduced a commercial dimension to visitor access at the world's most famous geothermal field — a tension between private landholding and public expectation that would persist for another century. ^[9]

The ownership saga continued into the twentieth century alongside increasingly interventionist measures to manage the geyser's behaviour for visitors. Eruptions had become irregular and infrequent, frustrating tourists who arrived expecting the famous spectacle. In 1935 the Icelandic businessman Sigurður Jónasson purchased the land for 8,000 Icelandic krónur, believing the Icelandic state should own this singular natural treasure, and donated it to the Icelandic people in perpetuity. ^[8] That same year a man-made channel was excavated to lower the local water table, temporarily restoring eruptions by reducing hydrostatic pressure in the conduit. ^[2] After the channel silted up, a more notorious stimulation method was formalised in 1981: the addition of soap directly into the geyser's bowl. The surfactant reduced surface tension in the water column, triggering eruptions on demand. On special occasions — royal visits, the Verslunarmannahelgin bank holiday, and other significant events — up to 40 kilograms of soap were poured into the vent to guarantee a performance for dignitaries and crowds. ^[9] The practice was curtailed on environmental grounds and formally ended by 1992. The damage caused by decades of artificial stimulation, combined with disputes over private land surrounding the state-owned fenced area, eventually prompted the governmental steps toward formal protected status for the entire field.

For most of recorded Icelandic history the Geysir geothermal field in Haukadalur was privately held farmland, and early efforts to bring it into public hands came to nothing. The local farming families who owned the ground had long hoped to sell to the government, but no state purchase materialized during the nineteenth century. That changed in 1894, when James Craig — a whiskey distiller from Ulster who would later become the first Prime Minister of Northern Ireland — visited the field in the summer of 1893 and bought the land the following spring for 3,000 Danish krone from the three sellers, Sigurður Pálsson, Jón Sigurðsson, and Greipur Sigurðsson. Craig erected fences and briefly collected an entrance fee, but family opposition to the expenditure led him to transfer the property to his friend E. Rogers, who had never visited Iceland and held no particular interest in the site. On Rogers's death his nephew Hugh Rogers inherited the field, leaving the world's most celebrated geothermal area in the hands of an absentee British family for roughly four decades. ^[1]

The period of foreign private ownership ended in 1935, when the wealthy Icelandic businessman and film director Sigurður Jónasson purchased the Geysir area for 8,000 Icelandic kronur and donated it outright to the Icelandic state, declaring that "the Icelandic state should own this unique treasure Geysir, and do everything it can to protect the area for future generations." Jónasson's gift transferred the central hot-spring field — including both the dormant Great Geysir and the reliably erupting Strokkur — into state ownership, but the surrounding and access lands remained in private hands. The result was a patchwork of ownership that persisted for the better part of a century, with the state holding roughly one third of the wider area and private landowners controlling the remainder. ^[1]

The mixed-ownership arrangement generated increasing conflict as tourism to the Golden Circle swelled in the twenty-first century. In early 2014 a landowners' company, Landeigendafélag Geysis ehf., erected a barrier and began charging visitors 600 Icelandic kronur to enter the area, arguing that the revenue was needed to fund development and maintenance of the site. The Icelandic state immediately contested the fee on the grounds that the fenced core — including both major geysers — had been state property since the 1935 agreement. In April 2014 the South Iceland District Court ruled the admission charge unlawful, found that the company lacked legal standing to levy fees on state land, and ordered it to cease collecting admission and to pay 500,000 kronur in court costs. The ruling confirmed the state's ownership of the principal geothermal features but left unresolved the status of the access routes and surrounding parcels controlled by private landowners. ^[2]

Following the court ruling the government moved toward acquiring the remaining privately held land. By December 2016 an agreement in principle had been reached for the state to purchase the surrounding parcels from the landowners, and full state ownership of all routes of access to the site was completed by 2017. With a consolidated ownership position secured, the Ministry for the Environment and Natural Resources was able to begin preparing the legislative framework for formal protection of the area. The timing was also shaped by the dramatic growth of tourism: the Geysir field was by this period receiving up to approximately 6,000 visitors on peak days, and the absence of any protected status left the silica sinter terraces, fragile microbial mats, and rare vascular plants such as blue-water speedwell exposed to unregulated foot traffic. (https://icelandmonitor.mbl.is/news/nature_and_travel/2020/06/21/geysir_area_declared_protected/ and https://en.wikipedia.org/wiki/Geysir)

The formal protection came on 17 June 2020 — Iceland's National Day — when Minister for the Environment and Natural Resources Guðmundur Ingi Guðbrandsson signed the decree designating the Geysir geothermal area in Haukadalur as a natural monument (náttúruvætti) under Iceland's nature-conservation legislation. The minister described the timing as fitting: "There are few other things as appropriate to do on National Day than to officially protect Geysir and its surroundings." The protected zone covers approximately 3 km² (about 1.2 sq mi) and encompasses the full suite of geothermal features, including the Great Geysir, Strokkur, Blesi, Sóði, Litli Geysir, Litli Strokkur, Vigdísarhver, Háahver, Sísjóðandi, and Óþeirrishola, as well as Mount Laugarfell (187 m / 613 ft), a rhyolite hill rising from the hot-spring terrace, and cultural heritage remains including the "king's stones" commemorating visits by three Danish monarchs between 1874 and 1921. The decree formalized conservation objectives that had previously had no legal force: preserving the geological formations, hot springs, microorganisms, and specialized vegetation, enabling scientific and educational use of the area, and providing a management framework for the high volume of visitors the site attracts as one of the most recognized stops on the Golden Circle route. ^[3]

Management of the protected natural monument was entrusted to the Environment Agency of Iceland (Umhverfisstofnun), which operated under the Ministry for the Environment and Natural Resources. On 1 January 2025 a reorganization of Iceland's environmental administration split the Environment Agency into two successor bodies: the Icelandic Environment and Energy Agency, which assumed regulatory and licensing functions, and the Nature Conservation Agency of Iceland (Náttúruverndarstofnun), which took over responsibility for protected areas, wild-bird and mammal conservation, and hunting regulation. The Geysir natural monument, along with Iceland's other protected areas, passed to the Nature Conservation Agency at that point. The conservation goals set out in the 2020 decree — stabilizing visitor flows, restoring areas disturbed by erosion, protecting the silica sinter and geothermal ecosystem, and supporting long-term sustainable access — guide ongoing management by the agency and cooperating local stakeholders in the Haukadalur valley. (https://ust.is/english/the-agency/news/newsitem/2025/01/02/Icelandic-Environment-and-Energy-Agency-and-Nature-Conservation-Agency-of-Iceland-established/ and https://ust.is/english/visiting-iceland/protected-areas/south/geysir-area/)

The Geysir Geothermal Area, set in the Haukadalur valley roughly 107 kilometres (66 miles) northeast of Reykjavík, is the most compact and visitor-ready of Iceland's three classic Golden Circle stops. Access to the geothermal field is free of charge, though a parking fee applies at the managed car park adjacent to the site. The attraction is defined by a short, well-signed loop of gravel and boardwalk paths threading through the active field, keeping walkers within metres of steaming vents, vivid pools, and the star of the show — Strokkur geyser. Most visitors who walk the full circuit and pause to watch multiple eruptions spend between 45 minutes and one hour on site. ^[1]

Strokkur is the heartbeat of any visit. The geyser erupts reliably every 6 to 10 minutes, hurling a column of superheated water between 15 and 40 metres (49 to 130 feet) into the air before collapsing back into its vent with a hollow gurgle. The build-up is as theatrical as the eruption itself: the pool's surface bulges into a deep blue dome of pressurised water for a second before the burst, giving attentive watchers just enough warning to ready a camera. Because Strokkur performs so frequently there is never a long wait, and the crowd around the roped-off viewing area cycles constantly. Wind direction matters — the splash zone beyond the rope can receive a shower of hot water when gusts are strong, so visitors are advised to check which side of the barrier ground is already wet and position themselves upwind. Unlike its neighbour, the Great Geysir is currently dormant, having last erupted naturally in 2016. Its wide, steaming basin remains a striking sight — historically it shot water to perhaps 170 metres (558 feet) at its 19th-century peak, and it was the feature that gave all geysers worldwide their name, from the Icelandic verb "geysa," meaning to gush. The two geysers sit only about 50 metres apart and are both visible from the main path. ^[2]

The loop path continues past a gallery of named springs that reward those who walk the full circuit rather than lingering only at Strokkur. Blesi, meaning "blaze" or "blaze of white," is formed by two side-by-side pools connected underground; the cooler northern pool appears a luminous, opaque blue caused by silica particles held in suspension, while the adjacent southern pool is crystal-clear boiling water — the visual contrast between them is one of the most photographed details in the field. A short distance away, Konungshver — the King's Spring — is named after Danish King Christian IX, who visited Haukadalur in 1874. Its colour shifts with the angle of light and geothermal chemistry, ranging from crystal clear to deep blue, green, or reddish-brown from day to day. Litli Geysir (Little Geyser) was once an active geyser in its own right, reportedly erupting to 10 metres (33 feet) before falling dormant toward the end of the 19th century; today it sits as a quietly bubbling pool. Smiður, meaning "the craftsman," is another dormant spring with its own legend: a local carpenter is said to have briefly coaxed it back to life before a royal visit in 1907. The elliptic greenish pool historically known as Fata was reportedly destroyed by geothermal shifts in 2004 and replaced by a feature informally called Fata II. Across the field, steaming fumaroles emit sulphurous vapour and in places the ground surface is stained yellow with mineral deposits, giving an immediate sense of the heat stored just below the surface. Boulders with engraved names mark each major attraction along the path, functioning as informal waymarkers. ^[2]

Safety at the Geysir field depends on a simple rule: rope and barrier lines are non-negotiable boundaries, not suggestions. Spring water temperatures exceed 100°C (212°F) throughout the field, and the thin mineral crust near pool edges can crack unexpectedly. Signs at the entrance and at individual features spell out prohibitions on throwing objects into the springs — historically, visitors once induced eruptions in the Great Geysir by adding soap, a practice that has since been banned because it permanently damaged the underground plumbing. Supervision of children is essential near all active features. The paths are mostly flat packed gravel, accessible to a wide range of visitors including families with young children. Rain gear is advisable in all seasons, and steam in cold weather can make paths briefly slippery near active vents. ^[3]

For visitors wanting elevation and perspective, the Laugarfjall rhyolite hill rises directly behind the geothermal field. The hill is the volcanic dome on whose lower slopes the entire Haukadalur geothermal system developed, and a short, informal trail climbs to a viewpoint from which the patchwork of steaming pools, white plumes, coloured mineral deposits, and surrounding farmland valley is visible in a single glance. The ascent is modest — Laugarfjall reaches roughly 187 metres (614 feet) above sea level — and the trail is generally considered a straightforward walk with some elevation gain. The panorama is particularly effective for understanding how compact the geothermal field actually is: what feels like a sprawling landscape when you are among the springs reveals itself from above to be a dense cluster of activity within a relatively small area of the valley floor. ^[4]

The Geysir Center, located directly across the road from the geothermal field, is the service hub for the entire stop. The complex includes Hotel Geysir (opened in 2019, 77 rooms and suites), a geothermal exhibition with multimedia content on volcanic processes and the Northern Lights, a full-service restaurant using local ingredients, a café and soup outlet, a large souvenir shop, and a spa. Its facilities are effectively the only food and restroom provision at this stop, as the geothermal field itself has no amenities, and the exhibition provides geological context that the open-air path does not. ^[5]

Geysir is the middle stop on the classic Golden Circle route, positioned roughly 45 minutes by car from Þingvellir National Park (the first stop, a UNESCO World Heritage rift valley with Viking parliamentary history) and only about ten minutes from Gullfoss, the powerful two-tiered waterfall that drops a combined 32 metres (105 feet) into the Hvítá river canyon and closes the loop. The three stops together form a roughly 300-kilometre (186-mile) circuit from Reykjavík that most tour operators complete in a day. Because of this positioning, Geysir receives a very high volume of organised tour groups in addition to self-drive visitors, and the area around Strokkur can be crowded at midday during summer. Arriving early in the morning or in the late afternoon significantly reduces competition for space at the rope line. Despite the crowds, the fundamental experience — watching a reliable geyser perform against an open Icelandic sky, strolling past pools in improbable blues and greens, and climbing a small hill to take in the valley — remains one of the most immediate and accessible encounters with active geothermal geology available to visitors anywhere in the world. ^[6]

Visitor access to the Geysir geothermal area itself is entirely free of charge, and the field remains open around the clock every day of the year. There are no gates or admission booths; visitors simply walk directly from the car park into the steaming landscape. Parking is available in a large lot immediately adjacent to the site on Route 35 (Biskupstungnabraut). The lot has historically been free, though Iceland's popular natural attractions have increasingly introduced paid parking through the Parka payment app, and a modest fee of around ISK 1,000 per car has been reported at Geysir (as of 2024); visitors should follow on-site signage for the current arrangement and payment method. Restrooms are located within the Geysir Center complex directly across the road, accessible during facility opening hours of roughly 09:00 to 18:00 in peak season with reduced hours in winter, while the geothermal field itself is reachable at all times. ^[1]

The Geysir Center, situated directly opposite the geothermal field on the south side of Route 35, is the hub of visitor services for the area. The complex brings together several establishments: Kantína is the main restaurant offering Icelandic and international dishes, a separate café and ice-cream shop serves lighter refreshments, and Supa provides quick soup and snack options. A large souvenir and outdoor-clothing shop stocks Icelandic brands, warm layers, and travel gear — useful if the weather turns cold without warning. A small exhibition on the geology and history of the geothermal area and the Golden Circle region is also housed within the complex. Additional amenities include a campsite for overnight stays, the nine-hole Geysir Golf course, and the Geysir Spa, whose design draws on the natural elements of the surrounding landscape. Free Wi-Fi is available throughout the facility. ^[2]

Accommodation directly on site is provided by Hótel Geysir, a four-star property that forms part of the Geysir Center complex and opened in 2019. The hotel offers 77 rooms and 6 suites, each with en-suite bathroom, flat-screen television, and coffee machine; some rooms include a bathtub. Guests have access to the hotel spa, and a buffet breakfast is served each morning; a buffet lunch is also available daily from 11:30 to 14:00 (as of May 2026). For a smaller option, the Litli Geysir Hotel sits a short walk from the main parking area and serves traditional Icelandic lamb and seafood. Several guesthouses and farm stays are scattered through the Haukadalur valley and the nearby village of Reykholt a few kilometres south. The town of Selfoss, roughly 55 kilometres (34 miles) away via Routes 35 and 1, offers a wider range of budget and mid-range hotels and is a common base for combining the Golden Circle with the South Coast. Many visitors also choose to day-trip from Reykjavík, which lies well within comfortable range for a full-day excursion. ^[3]

The Geysir geothermal area lies approximately 100 kilometres (62 miles) east of Reykjavík, with a typical driving time of around 90 minutes under normal conditions. The most common self-drive route follows Route 1 east out of the capital and then turns north onto Route 35 (Biskupstungnabraut) through the Biskupstungur farming district, arriving at Geysir in the upper Haukadalur valley. An alternative clockwise Golden Circle route begins by heading north on Route 36 to Þingvellir National Park, then continues via Routes 365 and 37 through the lakeside village of Laugarvatn before joining Route 35 south to Geysir. All roads on this circuit are paved and open year-round, though winter driving requires caution: studded or winter-rated tyres are mandatory in Iceland from November through mid-April. A standard two-wheel-drive car is adequate in summer and autumn; four-wheel drive provides additional confidence in winter. From Geysir, the celebrated Gullfoss waterfall is only about 9.8 kilometres (6 miles) further along Route 35 — a drive of roughly ten minutes — making the two attractions a natural pairing within a single morning or afternoon. Completing the classic Golden Circle loop back to Reykjavík via Þingvellir covers a total circuit of around 235 to 300 kilometres (146 to 186 miles) and takes six to eight hours including time at each stop. ^[4]

Those without a car can reach Geysir on any number of organised Golden Circle day tours that depart from Reykjavík daily throughout the year. Guided bus excursions operated by Reykjavík Excursions and numerous other operators typically run 6.5 to 8 hours and depart from the BSÍ Bus Terminal in central Reykjavík, with hotel pickup often available as an add-on. Standard Golden Circle bus tour prices begin at around USD 80 to 100 per adult (as of May 2026), though premium or small-group departures cost more. Booking in advance is recommended in summer, when popular departure times fill quickly. Geysir is a rewarding destination in every season. Summer's near-continuous daylight allows visits at any hour, but midday crowds are at their peak and early mornings or evenings are noticeably quieter. Winter visits, from November through February, can be the most atmospheric — thick steam columns rise against snow-white hillsides — and clear nights bring a chance of seeing the northern lights above the erupting Strokkur. Spring and autumn offer moderate crowds and dramatic skies. Icelandic króna (ISK) is the local currency; major credit and debit cards are accepted almost universally at the Geysir Center and its hotels, so carrying cash is not essential. ^[5]

Visitors should take the safety signage at the geothermal area seriously. The hot springs and mud pools at Geysir reach 100 degrees Celsius (212 degrees Fahrenheit), and the ground crust around active features can be fragile and thin. Marked paths and roped-off boundaries exist throughout the field and must be respected; stepping off the trail risks breaking through into superheated ground. Sturdy, closed-toe footwear with a firm grip is strongly recommended, as paths become wet and slippery from geyser spray and rain. Children should be kept close near active features, and visitors should be aware that the steam and spray from Strokkur — which erupts every 6 to 10 minutes to a height of 15 to 40 metres (50 to 130 feet) — can drift quickly with wind changes. With those precautions observed, the Geysir geothermal area is an exceptionally accessible natural spectacle requiring no specialist equipment, no guide, and no admission fee, making it one of the most straightforward major natural attractions in Iceland to visit independently. ^[4]

The Geysir Geothermal Area covers roughly 3 square kilometres (1.2 square miles) of the Haukadalur valley, yet it is one of the most visited natural sites in Iceland and one of the most famous geothermal fields on Earth. That combination of extreme geological delicacy and extreme tourist popularity has made conservation the defining challenge at Geysir for more than a century. The surface of the field is draped in geyserite, the brittle silica sinter deposited as superheated water cools at each vent rim. This mineral crust takes thousands of years to accumulate; researchers estimate that the great Geysir is roughly 10,000 years old based on the surrounding sinter mound, which measures 18 metres (59 feet) across. ^[1] The subsurface plumbing that sustains geyser eruptions is equally fragile: the narrow silica-lined conduits directing water upward can be permanently blocked by debris, water-table changes, or interference with the hydrothermal reservoir. A drainage ditch cut in 1935 to revive the dormant Geysir temporarily lowered the water table and triggered renewed eruptions, but within decades the channel became clogged with freshly precipitated silica and eruptions again became rare, demonstrating that even well-intentioned interventions can introduce irreversible consequences. ^[1]

The history of direct human interference with the springs is long and damaging. From 1981, soap was introduced into Geysir's vent to trigger eruptions on demand for visiting dignitaries and tourists; the surfactant lowers surface tension and destabilises the pressure equilibrium, forcing an eruption. The practice continued in various forms until the early 1990s, when additions became rare, before the government finally stopped the intervention entirely, amid concern that repeated forced eruptions were gradually degrading the vent structure. ^[1] At geyser fields worldwide, thrown objects have caused even more abrupt permanent damage: at Yellowstone, Minute Geyser permanently ceased erupting in 1947 after a rock lodged in its vent, and Morning Glory Pool was so fouled by debris over 150 years that its internal plumbing changed permanently. ^[2] Such examples explain why throwing any object into thermal features at Geysir is now strictly prohibited: a single obstruction in the silica conduits of Strokkur or the dormant Geysir could eliminate activity that took millennia to develop. ^[3]

Tourism pressure on this small field intensified dramatically as Iceland's visitor numbers surged from under 500,000 in 2010 to more than two million by 2017. ^[4] The Golden Circle route, linking Geysir with Thingvellir National Park and Gullfoss waterfall, became the most heavily trafficked tourist circuit in the country, concentrating an enormous share of those arrivals into a handful of tiny sites. At Geysir, foot traffic on the warm, moisture-laden ground around the vents accelerates erosion and fractures the brittle mineral crust in ways that cannot naturally repair within any human timescale. Visitors straying off marked paths also trample thermophilic microorganisms and rare plant species, including the blue water speedwell, whose threatened population occupies a narrow thermal niche at the field's margins. ^[3] The physical safety hazard compounds the conservation problem, since the ground near active vents reaches scalding temperatures and is thermally unstable, meaning a visitor who steps off a designated path risks both personal injury and irreversible damage to the sinter beneath their feet.

Beyond tourism, the broadest existential threat to the Geysir field comes from geothermal energy extraction. Iceland relies heavily on geothermal power, and the Haukadalur valley sits above the same hydrothermal systems that drive the geysers. Worldwide, approximately 260 geysers have been permanently extinguished by geothermal well withdrawal, representing roughly 23 percent of the planet's original endowment of about 1,194 geysers. ^[5] When wells lower reservoir pressure, the reduced hydraulic head is insufficient to drive geyser discharge and eruptions cease; geysers almost never recover once quenched, because cooling of the subsurface conduits allows new mineral deposits to seal the plumbing permanently. Iceland's own record illustrates the scale of the risk: approximately 46 geysers, representing 75 percent of the country's original endowment, were extinguished by twentieth-century geothermal development. New Zealand lost about 100 geysers, also 75 percent of its total, and in Nevada the entire Beowawe field of 30 geysers and the Steamboat Springs field of 26 geysers were both driven to complete extinction by geothermal wells. ^[5] Geysir's formal protection is partly a bulwark against this risk, signalling that preserving the hydrothermal system's integrity takes precedence over extraction in or near the protected zone.

On 17 June 2020, Minister for the Environment and Natural Resources Gudmundur Ingi Gudbrandsson signed the declaration protecting the Geysir area as a natural monument, stating it was designated "for the benefit of the whole world, because this is one of the world's best known hot spring areas." ^[6] The protection targets the unique geological formations, hot springs, microorganisms, and rare vegetation, and it was preceded in 2017 by the Icelandic government completing its purchase of the property to ensure full public ownership of all access routes. ^[1] Oversight now falls to the Nature Conservation Agency of Iceland, which assumed protected-area management when the former Environment Agency of Iceland (Umhverfisstofnun) was reorganised into two successor agencies on 1 January 2025. ^[7] On the ground, management consists of boardwalks and rope barriers channelling visitors along defined routes and off the sinter aprons around vents, warning signs marking zones of scalding water and unstable ground, and a strict no-drone designation. To distribute foot traffic more broadly, a new circular walking path was added in 2024 to reduce compaction pressure concentrated near the most popular vents. ^[8] The lesson Geysir encodes for conservation is one of irreversibility: the sinter accumulated over 10,000 years, the conduit geometry producing Strokkur's reliable eruptions took centuries of mineralisation, and geyser fields eliminated by drilling elsewhere have proved impossible to restore. Sustaining the field into the future requires enforcing the prohibition on introducing any substance into the springs, maintaining visitor infrastructure to absorb Golden Circle pressure, and monitoring the subsurface hydrothermal system for any sign of pressure change from regional geothermal activity. ^[3]