Queensland is a state in north-eastern Australia, the second-largest and third-most populous of the Australian states. 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 the Pacific Ocean; to its north is the Torres Strait, separating the Australian mainland from Papua New Guinea, and the Gulf of Carpentaria to the north-west. With an area of 1,723,030 square kilometres (665,270 sq mi), Queensland is the world's sixth-largest subnational entity; it is larger than all but 16 countries. Due to its size, Queensland's geographical features and climates are diverse, including tropical rainforests, rivers, coral reefs, mountain ranges and sandy beaches in its tropical and sub-tropical coastal regions, as well as deserts and savanna in the semi-arid and desert climatic regions of its interior.