Unnamed Crater in Vastitas Borealis (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)

This image covers part of a large Impact Crater located in the Northern Plains of Mars (Vastitas Borealis Region). The Crater is old and has been heavily modified by ground ice processes. The most prominent of these processes is the network of Polygonal Fractures visible throughout the image.
These landforms are created when temperature changes over the course of a year cause ice in the ground to first expand, then contract and, in the end, break. The ground moves fractionally every time this occurs.

At the center of the frame it can be seen that this - repetitive - process has caused the shifting of rocks and boulders through the Surface of the Crater, thus causing them to line up along the Fractures and then form some interesting geometric patterns.