Queensland (locally /ˈkwiːnzlænd/ KWEENZ-land, abbreviated as Qld) is the second-largest and third-most populous state in the Commonwealth of Australia. Situated in the north-east of the country, it is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean. To its north is the Torres Strait, with Papua New Guinea located less than 200 km across it from the mainland. The state is the world's sixth-largest sub-national entity, with an area of 1,852,642 square kilometres (715,309 sq mi). As of 15 May 2018, Queensland had a population of 5,000,000, concentrated along the coast and particularly in the state's South East. The capital and largest city in the state is Brisbane, Australia's third-largest city. Often referred to as the "Sunshine State", Queensland is home to 10 of Australia's 30 largest cities and is the nation's third-largest economy. Tourism in the state, fuelled largely by its warm climate, is a major industry. Queensland was first inhabited by Aboriginal Australians and Torres Strait Islanders. The first European to land in Queensland (and Australia) was Dutch navigator Willem Janszoon in 1606, who explored the west coast of the Cape York Peninsula near present-day Weipa. In 1770, Lieutenant James Cook claimed the east coast of Australia for the Kingdom of Great Britain. The colony of New South Wales was founded in 1788 by Governor Arthur Phillip at Sydney; New South Wales at that time included all of what is now Queensland, Victoria and Tasmania. Queensland was explored in subsequent decades until the establishment of a penal colony at Brisbane in 1824 by John Oxley. Penal transportation ceased in 1839 and free settlement was allowed from 1842. The state was named in honour of Queen Victoria, who signed on 6 June 1859 Letters Patent separating the colony from New South Wales. Queensland Day is celebrated annually statewide on 6 June. Queensland was one of the six colonies which became the founding states of Australia with federation on 1 January 1901.