Australia, officially the Commonwealth of Australia, is a country in the southern hemisphere comprising the mainland of the world's smallest continent, the major island of Tasmania, and numerous other islands in the Indian and Pacific Oceans. Neighbouring countries include Indonesia, East Timor, and Papua New Guinea to the north, the Solomon Islands, Vanuatu, and New Caledonia to the north-east, and New Zealand to the south-east.
Australia's landmass of 7,617,930 square kilometres (2,941,300 sq mi) is on the Indo-Australian Plate. Surrounded by the Indian and Pacific oceans, Australia is separated from Asia by the Arafura and Timor seas. Australia has 34,218 kilometres (21,262 mi) of coastline (excluding all offshore islands).