Rain in the Australian desert forms into rivers, channelled by the mountains. The Finke River has been cutting its course out of Australia's central ranges for nearly 300 million years and is thought to be one of the oldest rivers on earth. It does not flow to the sea but heads inland, further into the desert. Along its 700 kilometre route it transforms the dry lands beyond the mountains, providing precious water holes. And even when the water is not apparent on the surface, trees can reach the water that has seeped underground.