False-colour image of the volcanic edifice on the surface of Venus, made by the Magellan radar mapping spacecraft in March 1991. This edifice is in the Eistla Regio in the southern hemisphere of Venus. It is 66km across at the base and has a slightly concave summit 35km in diameter. To the west (top) the rim of the structure has been breached by a lava flow from the small dark summit peak. To the west of the edifice are also some collapsed pits between 2 and 10km in diameter. This structure is unlike any other previously observed. The black square is an area where insufficient radar data has been gathered.