It covers a rather vaguely defined area of about 245,000 square kilometres (95,000 sq mi) behind the northern coast from the Northern Territory capital of Darwin across to Arnhem Land with the Indian Ocean on the west, the Arafura Sea to the north, and the Gulf of Carpentaria to the east, and with the almost waterless semi-arid interior of Australia to the south, beyond the huge Kakadu National Park.

The well-known town of Alice Springs is located further south, in the arid southern part of the Northern Territory, sometimes referred to by Australians as the Red Centre.

The landscape is relatively flat with river floodplains and grasslands with eucalyptus trees along with rocky areas and patches of rainforest, and in western Arnhem Land a high rugged sandstone plateau cut through with gorges, much of which is in Kakadu National Park.

The climate is tropical monsoon with a wet and dry season, bringing the highest rainfall in northern Australia (over 1,200 mm (47 in) per year).

A belt of transitional tropical savannas and woodlands (Carpentaria, Kimberley, and Victoria Plains) lies between the Top End and the semi-arid mulga scrubland, mallee, and sand dunes of Australia's centre.