You can search for images taken by all Mars-orbiting spacecraft from Viking (1976) to the current day. The map-based search engine allows you to browse image footprints projected on background maps of the Martian surface.
The missions include Viking 1 and 2, the Mars Orbiter Camera (MOC) on Mars Global Surveyor, the Thermal Emission Imaging System (THEMIS) on Mars Odyssey, the Context Camera (CTX) and HiRISE Camera on Mars Reconnaissance Orbiter, and the High Resolution Stereo Camera (HRSC) on the Mars Express orbiter.
Web Map Mars
Search for Mars images using a base map of the plane.
NASA/JPL-Caltech/Arizona State University