Papandayan is a complex stratovolcano with four large summit craters, the youngest of which was breached to the NE by collapse during a brief eruption in 1772 and contains active fumarole fields.  The broad 1.1-km-wide, flat-floored Alun-Alun crater truncates the summit of Papandayan, and Gunung Puntang to the north gives the volcano a twin-peaked appearance.  Several episodes of collapse have given the volcano an irregular profile and produced debris avalanches that have impacted lowland areas beyond the volcano.  A sulfur-encrusted fumarole field occupies historically active Kawah Mas ("Golden Crater"). 

Source: GVP, Smithsonian Institution