The summit of Nyamuragira volcano is truncated by 2 x 2.3 km wide caldera whose floor is partially covered by unvegetated historical lava flows. This view from above the SW caldera rim shows a crater on the far side of the caldera (upper left) that was the site of a lava lake, active since at least 1921, which drained in 1938 at the time of a major flank eruption. Photo by Simon Carn, 2004 (TOMS Volcanic Emissions Group, University of Maryland, Baltimore County).