DEVIL'S MARBLES Local Aboriginals believe the rock formations they call Karlu Karlu are the eggs of the Rainbow Serpent, said to have created the Earth during the Dreamtime. They form one of the world's oldest religious sites, located near Wauchope in the Northern Territory. These chunks of granite, buried in a sea of sandstone, have been exfoliated by wind and sand to their current spheres, some of which are four metres in diameter. A few have been split apart by extremes of desert temperature between night and day, and in another few million years, just a few pebbles will be left. See www.northernterritory.com