The Aborigenes live in the Outback, one of the hottest and wildest deserts in the world. 
It covers 2/3rd (two thirds) of the continent. 

The landscapes are varied. 
In the Northern region, there is a tropical rain forest. 
In the central region, there is the desert. 
The Outback is desolate. There is nobody, no food, no water or communication. 

For example, each day it's 100°F and each night, it's freezing. 

-> The desert is uninhabitable. 
The conditions of living are severe, harsh, and unforgiving.