Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of 7,617,930 square kilometres (2,941,300 sq mi), Australia is the largest country by area in Oceania and the world's sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a megadiverse country, and its size gives it a wide variety of landscapes and climates, with deserts in the center, tropical rainforests in the northeast, and mountain ranges in the southeast. Canberra is the nation's capital, while the five largest cities are Sydney, Melbourne, Brisbane, Perth, and Adelaide. Australia's demography has been shaped by centuries of immigration, with immigrants accounting for 30% of the country's population, the highest proportion among major Western nations.

Source: Wikipedia