Nullarbor

Nullarbor National Park lies approximately 300 kilometres west of Ceduna along the Great Australian Bight, protecting one of the world's most exceptional cave landscapes and the dramatic Bunda Cliffs that plunge over 120 metres into the Southern Ocean. The park encompasses over 250 limestone caves including the extraordinary Old Homestead Cave with its 34-kilometre extent. The iconic Bunda Cliffs stretch for 200 kilometres and from May to October provide some of the world's best whale watching as southern right whales gather below to breed and calve. The Heritage-listed Koonalda Cave contains ancient Aboriginal rock art and archaeological evidence of human occupation during the last ice age, when sea levels were lower and the region was more habitable.

The park's most spectacular wildlife spectacle is the southern right whale congregation that occurs from May to October each year along the Bunda Cliffs. Mothers with calves can be observed from clifftop lookouts sometimes only metres above the whales as they breach, slap the water, and nurse their young in the relatively sheltered waters below the cliffs. Hairy-nosed wombats—the world's largest wombats—inhabit warrens across the Nullarbor Plain. Dingo packs patrol the plain, and southern hairy-nosed wombats are their primary prey. Seabirds including Cape gannets, white-capped albatross, and sooty shearwaters forage in the offshore waters. Reptiles including dragon lizards and blue-tongue lizards are common on the limestone pavement.

The Nullarbor Plain's vegetation is deceptively simple: a vast expanse of saltbush and bluebush chenopod shrubland on thin calcareous soils over impervious limestone. The near absence of trees across hundreds of kilometres of the plain is responsible for the name Nullarbor (from Latin nullus arbor, meaning 'no trees'). Small pockets of mallee eucalypts occur in areas with slightly deeper soil development along the plain's southern margins. The coastal cliff edges support distinctive wind-pruned shrubs including coastal daisy bush and native rosemary. Underground cave systems harbour unique cave-adapted invertebrates including blind cave spiders and cave crickets.

The Nullarbor Plain is the world's largest semi-arid karst landscape, formed from Tertiary limestone deposited as shallow marine sediments 25–15 million years ago when a shallow sea covered the area. The limestone is flat-lying, barely deformed, and exceptionally pure, creating ideal conditions for karst development through dissolution by slightly acidic rainwater. Over millions of years, this process has created the world's most extensive cave system beneath the apparently flat plain surface. The Bunda Cliffs represent the ancient edge of this limestone platform, where the sea has gradually undercut and collapsed the cliff face. Koonalda Cave is a large natural cave that provided shelter and water for Aboriginal peoples during the last ice age.

The Nullarbor experiences an extreme semi-arid continental climate. Annual rainfall averages 250 millimetres, concentrated in winter. Summer temperatures are punishing, regularly exceeding 45°C on the exposed plain. Winter provides more moderate temperatures of 10–20°C during the day, though nights can be cold. The plain is notoriously windy, with persistent easterly and westerly winds creating significant dust conditions. The coastal Bunda Cliffs are exposed to persistent westerly swell, making the sea below the cliffs rough for much of the year. Spring and autumn provide the most comfortable visiting conditions.

The Mirning people are the traditional custodians of the Nullarbor coast, and Koonalda Cave is a significant cultural site associated with ancient spiritual and practical activities. Koonalda provided water during periods of drought and was used as a flint quarry, with evidence of rock art scratched onto cave walls dating to over 20,000 years ago—among the oldest rock art evidence in Australia. The Mirning's Dreaming traditions link the Southern Right Whale with the creation of the Bunda Cliffs and coastal features. The transcontinental railway through the Nullarbor, constructed in 1917, dramatically changed access to the region and facilitated European settlement of the plain.

Nullarbor National Park was proclaimed in 1979, recognising the outstanding natural values of the limestone cave landscape and the Bunda Cliffs. The park was significantly expanded in subsequent decades to protect additional cave systems and coastal habitats. Koonalda Cave received Heritage listing reflecting its outstanding cultural and archaeological significance. Whale watching from the Bunda Cliffs gained recognition as one of Australia's premier wildlife experiences, and interpretation infrastructure was developed at key viewing points. The park is managed in consultation with Mirning traditional owners who maintain cultural obligations to the coastal Country.

The Bunda Cliffs whale watching lookouts—particularly near the Head of Bight visitor area—provide world-class whale viewing from May to October. Southern right whale mothers with calves are often seen so close to the base of the cliffs that individual behaviour can be observed in detail. The Head of Bight, just outside the national park boundary, is the main visitor access point with boardwalks and interpretation. Koonalda Cave can be visited by guided tour. The caves at Cocklebiddy and other sites accessible from the Eyre Highway provide extraordinary underground experiences. The vast Nullarbor Plain crossing itself is an iconic Australian road journey.

The Head of Bight whale watching facility (just outside the park boundary) is the main visitor hub with boardwalks and interpretation. Roadhouse accommodation at Nullarbor, Eucla, and Cocklebiddy along the Eyre Highway provides services for travellers. The park itself has limited facilities beyond directional signage and some viewing areas. The Eyre Highway traverses the southern edge of the plain, providing access along the plateau. Ceduna (approximately 300 km east) and Norseman in Western Australia (approximately 450 km west) provide the nearest full services. Entry to the park is via the Eyre Highway without a formal entry station.

Conservation management focuses on protecting the fragile karst landscape and its endemic cave fauna from damage, managing southern hairy-nosed wombat populations which can reach high densities leading to overgrazing, and maintaining the pristine condition of Koonalda Cave's rock art. Cave access restrictions limit disturbance to sensitive cave ecosystems. Feral camel and cat management programs operate across the broader plain. Southern right whale protection involves minimising disturbance at the Bunda Cliffs during the critical breeding and calving season, with guidelines for boat traffic and aircraft. Climate change threats include potential changes to the Southern Ocean upwelling systems that support the food chain sustaining whale migration.