Vast limestone plateau, southern Australia.
It lies along the south coast of western South Australia and eastern Western Australia, extending north from the Great Australian Bight to the Great Victoria Desert . It occupies 100,000 sq mi (260,000 sq km) of generally flat surface in bedrock. The name Nullarbor is derived from the Latin nullus arbor ("no tree"). The Nullarbor National Park preserves rare vegetation and fauna. The plain has many limestone caves, including Koonalda Cave, an archaeological site. The park is crossed by the world's longest stretch of straight railroad track (330 mi [530 km]).