Brisbane ( (listen) BRIZ-bən) is the capital and most populous city of the Australian state of Queensland, and the third-most populous city in Australia and Oceania, with a population of approximately 2.6 million. Brisbane lies at the centre of the South East Queensland metropolitan region, which encompasses a population of around 3.8 million. The Brisbane central business district is situated within a peninsula of the Brisbane River about 15 km (9 mi) from its mouth at Moreton Bay, a bay of the Coral Sea. Brisbane is located in the hilly floodplain of the Brisbane River Valley between Moreton Bay and the Taylor and D'Aguilar mountain ranges. It sprawls across several local government areas, most centrally the City of Brisbane, Australia's most populous local government area. The demonym of Brisbane is "Brisbanite".The Turrbal, a Durabalic tribe, were the earliest inhabitants of the area, and referred to it as Meeanjin.