Unnamed Crater with Gullies and Dunefield in Terra Cimmeria (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)

In this frame, taken by the NASA - Mars Odyssey Orbiter during its 49.393rd orbit around the Red Planet, several Gullies of different shapes, depths and sizes located on the Southern Rim of an Unnamed Impact Crater in Terra Cimmeria can be seen. As you may easily notice, there are way more Gullies on the North-facing Inner Rim (such as the Southern Inner Rim) of this Unnamed Crater, and the reason of such a remarkable difference is found, most likely, in the circumstance that the Southern Region of the Crater itself gets more Sun-related warming than the other one, which is corresponding to the South-facing Inner Rim (such as the Northern Inner Rim).
Also well visible towards the top of the picture, right at the base of the Northern Inner Slopes (Wall) of this Unnamed Cimmerian Impact Crater, there is a small and Dark Dunefield (probably formed - once you take into duly consideration the peculiar-looking shapes and surroundings of the Dunes forming it - by "Migrating Dunes". Dunes which may contain, among Dust, Rocky Sands and Volcanic Ashes, also a significant amount of Iron Oxide). It must be said, however, that a Surface Feature like this last one (---> the Dark Dunefield), is really very common, specifically at these Middle (Southern) Latitudes.

Latitude: 48,25° South
Longitude: 129,612° East
Instrument: VIS
Captured: February, 1st, 2013

This frame (which is an Original Mars Odyssey Orbiter b/w frame published on the NASA - Planetary Photojournal with the ID n. PIA 16266) has been additionally processed and then colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Mars Odyssey Orbiter and then looked down, towards the Surface of Mars), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team.