Which Australian desert is famous for the world’s longest parallel sand dunes?

The Simpson Desert is the Australian desert famous for the world’s longest parallel sand dunes.

It lies mainly in the Northern Territory and Queensland, with a smaller section in South Australia. The desert forms part of the vast Lake Eyre Basin, a mostly dry drainage system whose rivers occasionally flow toward Kati Thanda–Lake Eyre.

Many Simpson Desert dunes run roughly north–south and are separated by broad corridors. Some reach more than 200 kilometres in length, making the landscape especially distinctive. The dunes are generally stabilized by sparse vegetation, although their slopes and crests vary in color and height.

The Simpson Desert is sometimes confused with Australia’s largest desert, the Great Victoria Desert. It is also well known for the French Line, a remote track established in 1964 by survey teams and later used by four-wheel-drive travelers. Because there are no permanent roads across much of the region, access is difficult and often restricted during the hottest months.