This image along the southern interior floor of Gale Crater hosts many different landforms. Light-toned, scabby, and presumably hydrated materials on the crater floor are covered by large, darker-toned dunes.
The small crater, about 2 kilometers in diameter, in the middle of the image is filled with an enigmatic deposit that appears to have flowed into the crater from the south. [More at link]
[This image also accompanies a NASA/JPL release noting the arrival at Mars 10 years ago of the Mars Reconnaissance Orbiter, which carries the HiRISE camera.]