In this really suggestive VIS image, obtained by the NASA - Mars Odyssey Orbiter on September, 1st, 2009, during its 34.222nd orbit around the Red Planet, we can see two impressively big Dunes which are, most likely, made of Basaltic Sand. The two Dunes are the dark gray and ridged Surface Features visible at the upper and lower right (Dx) of the image. Just out of curiosity, this Area is located to the West of the large Martian Region known as Argyre Planitia.
Latitude (centered at approx.): 47,717° South
Longitude (centered): 303,532° East
This image (which is an Original Mars Odyssey Orbiter falsely colored and Map-Projected frame published on the NASA - Planetary Photojournal with the ID n. PIA 20248) has been additionally processed, magnified to aid the visibility of the details, contrast enhanced and sharpened, Gamma corrected and then re-colorized in Absolute Natural Colors (such as the colors that a normal 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.