Perth is the capital and largest city of the Australian state of Western Australia (WA). It is Australia's fourth most populous city, with a population of 2.1 million living in Greater Perth in 2020. Perth is part of the South West Land Division of Western Australia, with most of the metropolitan area on the Swan Coastal Plain between the Indian Ocean and the Darling Scarp. The city has expanded outward from the original British settlements on the Swan River, upon which the city's central business district and port of Fremantle are situated. Perth city is located on land on which the Whadjuk Noongar, an Aboriginal people of the south west of Western Australia, have lived for what is considered "a relatively conservative estimate of around 50,000 years".