Orientale Basin, or Mare Orientale, a multiringed impact basin on the Moon, in an image made in 1967 by the Lunar Orbiter 4 spacecraft. Two widely spaced ring structures, which are inward-facing faults called megaterraces, surround the initial excavation cavity (partially flooded with lava). The outer megaterrace, named the Cordillera Mountains, is 930 km (580 miles) in diameter.