Recommended for desktop backgrounds. I'm looking forward a higher resolution version. From the ESA site:
It shows an unnamed impact crater located on Vastitas Borealis, a broad plain that covers much of Mars's far northern latitudes, at approximately 70.5° North and 103° East.
The crater is 35 kilometres wide and has a maximum depth of approximately 2 kilometres beneath the crater rim. The circular patch of bright material located at the centre of the crater is residual water ice.
The colours are very close to natural, but the vertical relief is exaggerated three times. The view is looking east.