In this VIS image, taken by the NASA - Mars Odyssey Orbiter on April, 15th, 2014, and during its 54.716th orbit around the Red Planet, we can see, once again, a large number of unusually-shaped Dunes (concentrated on the Right - Dx - of the frame) while, on the lower Left (Sx) side of the picture, it is clearly visible an ancient and Unnamed Impact Crater with a Sand-Sheet on its Floor, covered by Duneforms (in fact, what we are looking at now could possibly be a small, so-called "Migrating Dunefield").
Other interesting Surface Features, visible on the upper and central Left (Sx) portion of the frame, are, in our opinion, as IPF, small and extremely smooth Vertical Reliefs (like tiny Hills and Buttes), all covered by a thin layer of Dust and, most likely, also by a really minimal amount of Residual Frost.
All these fascinating Surface Features are found on the Margin of the Martian Region known as Olympia Undae: a vast (---> extremely wide) Dunefield (actually, an "Erg", such as a Sea of Dunes) located near and all around the North Pole of Mars.
Latitude (centered): 78,7802° North
Longitude (centered): 182,8310° East
This image (which is a crop taken from an Original Mars Odyssey Orbiter b/w and Map-Projected frame published on the NASA - Planetary Photojournal with the ID n. PIA 18496) has been additionally processed, magnified to aid the visibility of the details, contrast enhanced and sharpened, Gamma corrected 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.