This animation, made of black and white images taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express spacecraft, shows an unusual 'rock glacier' in the eastern Hellas region.

This unusual ‘hourglass’-shaped structure with flow features, most likely formed by glaciers or ‘block’ glaciers, is located in Promethei Terra at the eastern rim of the Hellas Basin, at about latitude 38º South and longitude 104º East.