Simpson Desert

The Simpson Desert is Australia's fourth-largest desert, covering about 176,500 square kilometers of red sandy plains and dunes across the Northern Territory, South Australia and Queensland. Known to the Wangkangurru Yarluyandi people as Munga-Thirri, it holds the world's longest parallel sand dunes, running north to south and held in place by vegetation, ranging from about 3 meters high in the west to around 30 meters in the east, with the largest dune, Big Red or Nappanerica, reaching 40 meters. Beneath the desert lies part of the Great Artesian Basin, one of the world's largest inland drainage systems, and natural springs such as Dalhousie Springs bring water to the surface, though bore extraction has reduced spring flows in recent years. The desert's extremely hot, dry climate brings only about 150 millimeters of rain a year, mostly in summer, when temperatures average 28 degrees Celsius but can exceed 50.