The center of the Gusev crater with the landing site of the NASA Spirit rover marked with a cross. The image was taken by the HRSC instrument in colour and 3D on 16 January 2004 from a height of 320 km.
Gusev is a large crater about 160 km in diameter. Scientists believe that the crater was covered by standing water, maybe in the form of a lake, early in the history of Mars.
This is a section of a larger picture, accessable as a high resolution download, which covers 60 m from top to bottom. North is at the top. (Note the green colouring is an effect of image processing)