About 100 km south of Tennant Creek in Australia’s Northern Territory along the Stuart Highway, granite boulders varying in size from 50 centimeters up to six meters in diameter lie scattered across the valley, with some precariously balanced on top of others. The local Aboriginal people to whom the area is of great spiritual significance, call the boulders ‘Karlu Karlu’ which means ‘round rock’ and, according to Dreamtime stories, are the eggs laid by the Rainbow Serpent. In English, the boulders are aptly named ‘The Devil’s Marbles’. They can be viewed from up close by following a network of tracks with informative signs that explain how this fascinating phenomenon came about - and how it continues to change the landscape.