Tasmania (; abbreviated as Tas and known colloquially as "Tassie") is an island state of the Commonwealth of Australia. It is located to the south of the Australian mainland, separated by Bass Strait. The state encompasses the main island of Tasmania, the 26th-largest island in the world, and the surrounding 334 islands. The state has a population of over 515,000 , almost half of which resides in the Greater Hobart precinct, which forms the metropolitan area of the state capital and largest city, Hobart.