Northern Territory, self-governing territory of Australia, occupying the central section of the northern part of the continent.Ayers Rock (Uluru) Ayers Rock (Uluru) The Northern Territory is bounded by the Timor and Arafura seas to the north and by Western Australia to the west, Queensland and the Gulf of Carpentaria to the east, and South Australia to the south. It is approximately 1,000 miles (1,600 km) from north to south and 600 miles (970 km) from east to west and occupies more than one-sixth of the Australian landmass. It is largely tropical in the north and semiarid in the far south.