The Devil's Marbles (or its Aborigine name Karwekarlwe) can be located near Wauchope which is 114km south of Tennant Creek in Australia's Northern Territory. These are spectacular mass of boulders that rise up to 4 metres high and 7 metres wide piled up on each other. The Marbles are located in a traditional Aboriginal sacred site and are important to the local tribe. The Arrente people believe that the Karwekarlwe are eggs of the Rainbow Serpent.

The remarkable geological formations have been formed by spheroidal weathering. Signs along the pathways describe how the boulders were formed by a combination of mechanical weathering (which cracked the rocks) and chemical weathering (which flaked the surface off). The boulders were originally part of a solid mass of coarse grained granite which formed deep within the earth's surface about 1640 million years ago. Erosion has since stripped away the overlying material, and weathering processes have shaped them into the "marbles" as they appear now. As the molten magma cooled and hardened to form granite the mass shrank and cracked and these cracks known as joints effectively split the granite body into a series of tight fitting blocks.

One of the Marbles were removed from the site and was placed on the top of the grave to John Flynn who was the founder of the Flying Doctor Service in Central Australia. At the time, this was seen as a way of remembering his link to the outback, but in later decades it was a source of great controversy because the rock was removed from a sacred site without the direct permission of the tribal elders. In the late 1990s, a boulder swap was arranged, and the missing marble was removed from the grave, cleaned, and returned to its original place. The grave is now marked with a similar boulder donated by the local Arrernte people.