Papandayan is a complex stratovolcano at the S end of a curved volcanic massif with Kendang volcano ~9 km away at the N end, Gunung Puntang ~3.5 km NNE, and Gunung Jaya ~6 km NNE. Several episodes of collapse have created an irregular profile and produced debris avalanches that have affected lowland areas. The summit area includes four large craters, including the 1.1-km-wide, flat-floored Alun-Alun crater. A sulfur-encrusted fumarole field occupies the active Kawah Mas ("Golden Crater"). The first reported eruption, in 1772 CE, included a collapse of the NE flank and a debris avalanche that destroyed 40 villages and killed almost 3,000 people. Smaller phreatic eruptions occurred during 1923-25, 1942, and 2002.