Nullarbor Plain: Australia's Largest Limestone Region

The Nullarbor Plain, stretching more than 200,000 square kilometres (77,000 square miles) across southern Australia, is one of the planet’s largest limestone regions. The flat, treeless expanse lies between the Great Australian Bight and the Southern Ocean, forming a continuous limestone plateau that dominates the landscape of South Australia, Western Australia, and the Northern Territory.

Geologists explain that the plain originated when a shallow sea that once covered the area receded about 14 million years ago during the Miocene epoch. As the sea withdrew, the underlying limestone was exposed and subsequently eroded, leaving behind the stark, featureless terrain that characterises the Nullarbor today. The region’s geological history has attracted scientific interest, and its unique environment supports a range of specialised flora and fauna adapted to the arid conditions.

The Nullarbor remains a significant natural landmark for both scientific research and tourism. Its vast, limestone‑rich landscape continues to be studied for insights into ancient marine environments and the processes that shape large-scale karst landscapes worldwide.