Mars digital-image mosaic merged with color of the MC-15 quadrangle, Elysium region of Mars. The Elysium quadrangle includes relatively smooth lowland plains immediately north of the more cratered highlands. The plains are interrupted on the northwest by two large shield volcanoes, Elysium Mons and Albor Tholus. The plains are also marked by an elongate crater, Orcus Patera, at the east boundary and a band of knobby terrain that extends northeastward through the eastern part. Latitude range 0 to 30 degrees, longitude range -180 to -135 degrees.