Another odd but beautiful image of Mars, showing a cone-shaped hill with sand dunes wrapping around it. The formation is in the Ganges Chasma region, and the image was taken by the HiRISE camera on the Mars Reconnaissance Orbiter. Mars has a lot of diverse geology, and this is another good example of that. Original images are here.
This is interesting, a recent HiRISE photo from the Mars Reconnaissance Orbiter spacecraft showing an oval pit or crater with an opening in the bottom (cropped here from one of the larger images) near Galaxias Chaos on Mars. The opening is also oval, and you can see some sand dunes on the bottom. How did it form? More images are available here.