Perth is the capital and largest city of Western Australia. It is separated from Adelaide (the nearest city with over one million inhabitants) by a distance of 2,139km, including the vast desert Nullarbor Plain.
Perth spreads out along a flat coastal plain, dissected by the Swan River, and spreads over the Darling Scarp to the east. The Indian Ocean coastline to the west is its only distinct physical boundary.
Perth has a population of over 1.8 million (2012), making it the fourth largest city in Australia.