Mars digital-image mosaic merged with color of the MC-28 quadrangle, Hellas region of Mars. The northwestern part includes the eastern half of the ancient large Hellas basin, defined by a rim of rugged mountain blocks that surrounds a nearly circular expanse of light-colored plains. The southwestern part is marked by part of the Amphitrites shield volcano and associated ridged plains that may be basaltic lava flows. The northern part includes a low, dissected shield volcano, Hadriaca Patera, and associated plains that may be basaltic lava flows. These plains are dissected in places by large sinuous channels. The eastern part is dominated by high-standing heavily cratered highlands, perhaps uplifted by the Hellas impact event. Latitude range -65 to -30 degrees, longitude range -120 to -60 degrees.