New South Wales is a state on the east coast of Australia. It borders Queensland to the north, Victoria to the south, and South Australia to the west. Its coast borders the Tasman Sea to the east. The Australian Capital Territory is an enclave within the state. New South Wales' state capital is Sydney, which is also Australia's most populous city. In September 2018, the population of New South Wales was over 8 million, making it Australia's most populous state. Just under two-thirds of the state's population, 5.1 million, live in the Greater Sydney area.