Rising out of the red sand plains of the centre, the MacDonnell Ranges were pushed up when two ancient continents collided. After eons of churning geological forces and erosion, the worn-down stubs of that age-old range are one of Australia's few truly mountainous regions. The Western Arrernte people know it as Altyerre, the eternal land. Ancestral connections envelop the coloured hills as surely as silence and timelessness. The curved plateau of Watarrka National Park is quite a different landscape, with remarkable small features and equally rich in Aboriginal presence.