Geysir Geothermal Area

The Geysir Geothermal Area is a geothermal field in the Haukadalur valley of south-western Iceland, on the slopes of the Laugarfjall lava dome ^[1]. It was protected as a natural monument on 17 June 2020, and the protected area covers 1.2 km² ^[2]. It lies within a high-temperature area of about 3 km² with numerous hot springs ^[3]. With Þingvellir and the Gullfoss waterfall it is part of the Golden Circle, Iceland's most famous tourist route ^[1].

Its centrepiece is the Great Geysir, the spouting hot spring whose name gave English the word geyser ^[1]. The oldest written records of Geysir date to the 13th century ^[4]. Its activity has risen and fallen with earthquakes; after the South Iceland earthquakes of 2000 it revived for a while, and it was last known to erupt in 2016 ^[3]. Today the main attraction is Strokkur, about 50 metres south of Geysir, which erupts at regular intervals every few minutes in small but powerful eruptions that can reach 30 metres (https://en.wikipedia.org/wiki/Geysir; https://ust.is/english/visiting-iceland/protected-areas/south/geysir-area/nature-and-geology/).

Other hot springs in the area include Konungshver, Blesi, Litli Geysir, Óþerrishola and Sísjóðandi ^[3]. Around thirty smaller geysers and hot pools lie in the field, and detailed thermal mapping has identified 364 distinct hot areas ^[1].

The Geysir geothermal field is a sparse environment for animals: scalding ground, mineral-laden water and the constant discharge of steam exclude most of them from the active hot-spring zone. Its most distinctive life is the community of thermophilic microorganisms in the warm waters and runoff channels of the field.

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. ^[1]

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. ^[2]

The Arctic fox is the only land mammal native to Iceland; it reached the island at the end of the last ice age, walking over the frozen sea ^[3]. Other mammals have been introduced since the human settlement of Iceland ^[4]. The geothermal field is thus extraordinary at the microbial scale but unremarkable for large animals.

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 high-temperature area covers about 3 square kilometres (1.2 square miles), of which the protected Geysir area is a small part ^[1], and thermal mapping has identified 364 distinct hot areas in the field ^[2]. 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 ^[3]. 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, birch trees make an impression on the landscape, and the vascular plants of the area include self-heal, creeping thyme, hairy stonecrop, marsh cudweed and buck's-horn plantain ^[1]. Two geothermal vascular plants that are classified as species in some danger grow here, blue water-speedwell (Veronica anagallis-aquatica) and adder's-tongue (Ophioglossum azoricum), together with several geothermal mosses ^[1].

The Haukadalur valley is known for the Haukadalsskógur National Forest ^[4]). The protected Geysir area extends up to the forestry parking lot, and the forestry area has many hiking trails; the tallest tree in Haukadalsskógur grows by the stream in Svartagil ^[5].

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 high-temperature area covers about 3 square kilometres (1.2 sq mi), of which the protected Geysir area is a small part ^[2]. Geysir lies on the eastern slopes of Laugarfjall (187 m), a rhyolitic lava dome ^[1]. 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. ^[3] 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. ^[4] Because Strokkur does not empty between eruptions, it refills quickly and erupts at regular intervals every few minutes, in small but powerful eruptions that can reach 30 metres (98 ft) (https://ust.is/english/visiting-iceland/protected-areas/south/geysir-area/nature-and-geology/; https://en.wikipedia.org/wiki/Geysir). 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. Geological studies suggest that the geyser itself began forming about 1150 CE. ^[1] The oldest definitive accounts of the hot springs in their present form date to 1294, when earthquakes created several new hot springs. ^[1] Measurements by Robert Bunsen in 1846 showed Geysir erupting 45 to 54 metres (148 to 177 ft) high. Before 1896 it was almost dormant; in 1910 it erupted every 30 minutes, and by 1916 its eruptions had all but ceased ^[1].

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 earthquakes created several new hot springs, an earthquake in 1896 revived the Great Geysir to eruptions several times a day, and earthquakes in 2000 revived it again ^[1]; it was last known to have erupted in 2016 ^[2]. Strokkur's activity has also been affected by earthquakes, though less than Geysir's ^[1]. 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 area lies in Iceland's southern lowlands. Iceland has a subpolar oceanic climate (Köppen Cfc) near the southern coast and tundra inland in the highlands; the North Atlantic Current makes it more temperate than its latitude, just south of the Arctic Circle, would suggest, and the weather is notoriously variable ^[1].

The southern lowlands near the coast average around 1 °C (34 °F) in winter. The average July temperature in the south of the island is 10–13 °C (50–55 °F), and warm summer days can reach 20–25 °C (68–77 °F) ^[1].

Lowland wind speeds reach 18 metres per second (65 km/h) on 10–20 days a year, and thunderstorms are extremely rare, with fewer than five a year in the south of the island ^[1]. South of the polar circle the sun sets briefly in midsummer, but there are around two weeks of continuous daylight, and the aurora borealis is often visible at night in winter ^[1].

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]

Geological studies suggest that Geysir began forming about 1150 CE ^[2]. A geyser at the site is described by Saxo Grammaticus in Gesta Danorum, finished about 1206, but the oldest definitive accounts of the Haukadalur hot springs in their present form date to 1294, in the chronicle Oddaverjaannáll, when earthquakes caused significant changes in the landscape and created several new hot springs ^[2]. In records dated 1630 the geysers erupted so violently that the valley around them trembled, and the name Geysir first appears in written sources in 1647 ^[2]. The word derives from the Icelandic verb geysa, "to gush" ^[3]. Because unusual natural phenomena drew great interest in the Age of Enlightenment, the name became popular and has since been used for similar hydrothermal features worldwide ^[2]. Eggert Ólafsson and Bjarni Pálsson wrote in their travelogue of a 1750 visit that their main purpose was to see the nationally known geyser that erupts from a rock in Haukadalur ^[4].

By the early nineteenth century the spring had drawn natural philosophers from across Europe. In 1811 the geologist George Mackenzie first proposed that expansion of steam in a subsurface cavity explained Geysir's activity. ^[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. The research gave a better general explanation of the mechanism of geyser activity and contributed significantly to the more refined models used today. ^[2]

The "king's stones" in the protected area are relics of the visits of three Danish kings: Christian IX in 1874, Frederick VIII in 1907 and Christian X in 1921. Geysir was part of the Royal Road built for Frederick VIII's visit in 1907 ^[4].

Until 1894 the Geysir area was owned by local farmers. That year it was sold to James Craig, later Lord Craigavon and the first Prime Minister of Northern Ireland, who erected fences around the site and charged visitors an entrance fee (https://www.icelandreview.com/news/historian-explains-why-icelandic-government-owns-geysir/; https://en.wikipedia.org/wiki/Geysir). He later gave the area to a friend, and in 1935 Sigurður Jónasson bought the land back and gave it to the Icelandic people ^[4].

Geysir's activity has risen and fallen with earthquakes. Before 1896 it was almost dormant; an earthquake that year restarted eruptions several times a day, but by 1916 they had all but ceased ^[2]. In 1935 a channel was dug through the silica rim around the vent, lowering the water table and reviving activity until the channel clogged with silica ^[2]. In 1981 the ditch was cleared again, and eruptions could be stimulated on special occasions by adding soap; because of environmental concerns soap was seldom added during the 1990s ^[2]. Putting soap or any other substance into the hot springs is now prohibited ^[6].

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/; 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 area covers 1.2 km² (about 0.46 sq mi) ^[3] 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 Laugarfjall (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. ^[4]

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/; https://ust.is/english/visiting-iceland/protected-areas/south/geysir-area/)

The main sights are the hot springs. Strokkur erupts at regular intervals because, unlike Geysir, it does not empty between eruptions, and its eruptions can reach 30 metres; the Great Geysir has been dormant since its last known eruption in 2016 ^[1]. The many other hot springs include Blesi, Fata, Seyðirinn, Sóði, Litli Geysir, Óþerrishola, Litli Strokkur, Vigdísarhver, Smiður, Móri, Sísjóðandi, Konungshver and Þykkvuhverir ^[1]. For the protection of the sinter and for safety, all visitors must follow the marked walkways within the hot-spring area ^[2].

The hike up Laugarfjall is an accessible round trip with two observation platforms: one looks over the hot-spring area and the forestry, the other over Helludalur and Bjarnarfell ^[3]. Laugarfjall (187 m) is a rhyolite intrusion with many geological formations ^[4].

The protected area extends up to the forestry parking lot in Haukadalur, and the forestry area, Haukadalsskógur, has many hiking trails (https://ust.is/english/visiting-iceland/protected-areas/south/geysir-area/outdoor-activities-and-hiking-trails/; https://en.wikipedia.org/wiki/Haukadalur_(Bl%C3%A1sk%C3%B3gabygg%C3%B0)). The most popular leads to Svartagil, past Hákonarlundur and over Kaldilækur; the tallest tree in Haukadalsskógur grows by the stream in Svartagil, and walking on north-west under the slopes of Sandfell leads down into Gunnarslundur, a picnic spot, before the loop returns to the parking lot at Hákonarlundur ^[3]. A riding and hiking trail north of Laugarfjall also leads to the forestry, so it is possible to walk around Laugarfjall ^[3].

The Geysir area is managed and supervised by Iceland's environmental agency; it is patrolled all year round, and rangers maintain the area and provide information ^[1]. Since 1 January 2025 Iceland's protected areas have been the responsibility of the Nature Conservation Agency of Iceland ^[2].

Just outside the protected area are Hotel Geysir, Hotel Litli Geysir, and the shops and restaurants of the Geysir Center. There is a gas station at Geysir, the last one before the Kjölur route, and a campsite operated by Hotel Geysir under the southern slopes of Laugarfjall ^[1]. Geysir is one of the three classic stops on the Golden Circle, with Þingvellir and Gullfoss ^[3].

Rules in the protected area require visitors to keep to the marked walkways in the hot-spring area. Bathing in the hot springs and pools, throwing stones, coins, soap or other objects into them, breaking off or removing hot-spring crust, soil or stones, and cooking in the springs, except for the region's traditional bread baking, are all prohibited ^[4].

The protected Geysir area covers 1.2 square kilometres (0.46 square miles) of the Haukadalur valley ^[1], 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. Geological studies suggest that the Great Geysir began forming about 1150 CE. ^[2] 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. ^[2]

In 1981 the drainage ditch was cleared again, and eruptions could be stimulated on special occasions by adding soap to the vent; because of environmental concerns soap was seldom added during the 1990s ^[2]. The 2020 protection prohibits putting soap or any other substance into the hot springs and pools, throwing or discharging stones, coins, soap or other objects into them or their drainage, and bathing in them ^[1].

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. ^[3] 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. ^[4] 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. ^[2] 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] All visitors must follow the marked walkways within the hot-spring area, for the protection of the hot-spring crust and for safety ^[1]. The protection also promotes the restoration of disturbed natural surroundings to their former state as far as possible, and aims to keep the area ready to receive the large number of people who visit it each year ^[1].