The Nullarbor Plain ( NUL-ər-bor; Latin: nullus, "no", and arbor, "tree") is part of the area of flat, almost treeless, arid or semi-arid country of southern Australia, located on the Great Australian Bight coast with the Great Victoria Desert to its north. It is the world's largest single exposure of limestone bedrock, and occupies an area of about 200,000 square kilometres (77,000 sq mi). At its widest point, it stretches about 1,100 kilometres (684 mi) from east to west across the border between South Australia and Western Australia.