What is the Nullarbor Plain?

The Nullarbor Plain is a vast, almost completely flat and treeless arid region in southern Australia, stretching for about 1,100 kilometres along the Great Australian Bight from Norseman in Western Australia to Ceduna in South Australia. It covers about 200,000 square kilometres and is one of the largest single pieces of limestone bedrock in the world.

The name Nullarbor comes from the Latin words nullus (no) and arbor (tree), an apt description for most of the plain's central section. The treeless core sits on a thick layer of porous limestone laid down when the area was an ancient seabed, and the porous rock prevents trees taking root. Underneath the limestone lies an extensive cave system including the deepest dry caves in the southern hemisphere.

The Nullarbor is crossed by two of Australia's most famous transport corridors. The Eyre Highway, completed in 1976 and sealed throughout, runs from Norseman to Port Augusta and includes the longest straight stretch of sealed road in the world (146 kilometres without a bend) near Caiguna. The Indian Pacific railway, opened in 1970, includes the longest straight stretch of railway in the world (478 kilometres) between Ooldea and Watson.

Aboriginal nations including the Mirning, Wirangu, and Kokatha peoples have lived on the Nullarbor for tens of thousands of years and maintained knowledge of soakages and rock holes that made permanent occupation possible. Today the plain is sparsely inhabited, with roadhouses every 100 to 200 kilometres providing fuel, food, and accommodation. Major attractions include the Bunda Cliffs (where the plain meets the Southern Ocean in vertical 90-metre limestone walls), winter whale watching at the Head of Bight, and the Maralinga nuclear test site to the north.