The forested Salak volcano was constructed at the NE end of an eroded volcanic range. Satellitic cones occur on the SW flank and at the northern foot, and two large breached craters truncate the summit. One crater is breached to the NE and the westernmost crater was the source of a debris-avalanche deposit that extends 10 km WNW of the summit. Phreatic explosions have been recorded from a solfataric area at 1,400 m on the western flank. Salak volcano has been the site of extensive geothermal exploration.