Australia is the world's smallest continent and sixth-largest country. With proportionately more desert land than any other continent, Australia has a low population density. Lying completely in the Southern Hemisphere, Australia is bounded by the Indian Ocean on the west and south and by the Pacific Ocean on the east. These oceans merge on the north in the Arafura Sea between Australia and Indonesia and New Guinea, and on the south in the Bass Strait. The coastline length, estimated at 19,200 km (12,000 mi), is remarkably short for so large an area, a result of the relative lack of indentation. Major inlets other than the Gulf of CARPENTARIA and the GREAT AUSTRALIAN BIGHT are few.
A self-governing member of the Commonwealth of Nations, Australia celebrated its bicentennial in 1988z. It is a federation of five mainland states (NEW SOUTH WALES, QUEENSLAND, SOUTH AUSTRALIA, VICTORIA, WESTERN AUSTRALIA) and one island state (TASMANIA), as well as two territories (AUSTRALIAN CAPITAL TERRITORY, NORTHERN TERRITORY). The country's name derives from the Latin terra australis incognita, meaning "unknown southern land," which resulted from a confusion between Australia and Antarctica on early world maps.
In many ways Australia is unusual among continents. It lacks major relief features and has a high proportion of dry land. The continent's isolation from other landmasses accounts for its unique varieties of vegetation and animal life, and for the existence of a Paleolithic (Old Stone Age) culture among the Aborigines. Except for Antarctica, Australia was probably the last continent to be inhabited by humans and the last to be explored and settled by Europeans. It is the only continent comprising a single nation-state.
Dutch explorers first sighted Australia in the early 17th century. Capt. James COOK explored the east coast in 1770 and claimed the land for Great Britain. In 1778 the first settlement (SYDNEY) was founded at an excellent harbor on the southeast coast. British convicts played an important role in the territory's early history. The discovery of gold and other ores attracted immigrants, but Australia remained a primarily agricultural country until World War II.
Subsequent industrialization has been rapid, and today Australia ranks as one of the world's most economically developed countries, although vast areas of the interior, known as the Outback, remain all but uninhabited.