The south polar layered deposits are icy layers that have been deposited over millions of years, preserving a climate history of Mars. In this image the layers are well illuminated to accentuate the topography. A prior image of this location was acquired with the layered slope facing away from the sun, placing the layers in shadow. (The top of the cutout image is at a higher elevation.) https://photojournal.jpl.nasa.gov/catalog/PIA23098