Australia is a highly urbanised country, and outside these major urban areas the landscape becomes rural which eventually gives way to the 'bush', a term that refers to nature or natural areas of vegetation. Travelling further inland from the bush, the landscape becomes increasingly arid and less hospitible with fewer settlements. This area is known by the term, 'The Outback'.
The outback is actually the biggest area of desert on Earth outside of the Sahara in Africa. It also encompasses large areas of savannah grassland. Despite the harsh environment, little rainfall, and periods of extreme heat, it is home to big populations of kangaroos, emus, dingoes, and the Australian camel. Flora includes small shrubs and stunted trees. The longest fence in the world known as the Dingo fence, divides the outback from the main rural area of Australia. It was built to stop dingos from threatening livestock. It is an impressive 5,614 km (3,488 mi) long.
Early European exploration of the Australian outback was not common initially, as there was more interest in the fertile coastal areas. The first party to cross the Blue Mountains near Sydney was led by Gregory Blaxland in 1813. As early as 1819 some explorers attempted to follow the westward-flowing rivers to discover what was commonly believed to be an "inland sea". Instead it was found that these rivers ended up flowing into the Murray-Darling basin, and were tributaries of Australia's two main rivers, the Murray River and the Darling River. Between 1858 to 1861, John Stuart led six expeditions near Adelaide into the outback. Upon successfully reaching the north coast some 3000 km away, they returned without any loss of life. However, an epedition by Burke and Wills in 1860-61 resulted in the deaths of all but one.
Exploration of the outback still continues to this day mainly for discovering areas rich in minerals. As recently as 1983 a film team discovered one of Australia's most stunning landscapes, the Bungle Bungle range. The area is now protected as Purnululu National Park and a World Heritage Listing was given in 2003 for its outstanding natural value.
Over 90 percent of Australians live in cities. Despite this, the outback and the history of its exploration provides Australia with a cultural backdrop for stories and songs about bushrangers and swagmen (itinerant laborers in search of work). The traditional and popular Australian song Waltzing Matilda is about a swagman.