Perspective views of the surface of Mars can be derived from digital terrain models of the HRSC image data. In the background it can be seen how – millions of years ago – non-viscous lava ‘surged’ against the obstruction caused by the very much older Phlegra mountains and solidified. These lava flows probably came from the volcano Hecates Tholus. Isolated mountains with rounded shapes project out from the high plateau in the foreground. The relief between the hills and mountains has been marked by landslides and the movements of ice in the course of earlier glaciation.