The Simpson Desert is a large area of dry, red sandy plain and dunes in the Northern Territory, South Australia and Queensland in central Australia. It is the fourth-largest Australian desert, with an area of 176,500 km2 (68,100 sq mi).

The Northern Territory is an Australian territory in the central and central northern regions of Australia. The Northern Territory shares its borders with Western Australia to the west, South Australia to the south, and Queensland to the east. To the north, the territory looks out to the Timor Sea, the Arafura Sea and the Gulf of Carpentaria, including Western New Guinea and other islands of the Indonesian archipelago.