This VIS image shows part of the dune field located on the floor of Arkhangelsky Crater.
Note: The type of dunes present in this photo are known as barchan dunes, also known as crescent-shaped or transverse dunes. Barchans are generally wider than they are long. The slipfaces of the dune are on the concave side (the shorter, downward slope). These dunes form under winds that blow consistently from one direction (the side of the dune with the longer, upward slope; the "horns" of the dune are downwind, and point the general direction that the dune is moving).
Photo credit: NASA/JPL/Arizona State University