Phoenicis Lacus was formed by the uplift of the Tharsis volcanic plateau. The continual episodes of strong volcanic activity in Tharsis not only lifted the plateau, but also compressed Phoenicis Lacus, creating uplifted blocks and multiple fault lines at different orientations. Extension has taken place here, resulting in this characteristic horst-and-graben (cliffs and valleys) landscape. This image was obtained on 31 July 2010 using the High-Resolution Stereo Camera (HRSC) on ESA’s Mars Express spacecraft. It combines data from the nadir channel and one stereo channel of HRSC. Stereoscopic glasses are required to see the 3D effect.