The symmetrical Matutum stratovolcano overlooks the city of General Santos in southern Mindanao, NW of Sarangani Bay, Philippines. The summit of the andesitic-to-dacitic volcano is truncated by a 320-m-wide crater that is breached by three gorges and has a 120-m-deep, densely forested floor. Widespread silicic pyroclastic flow deposits surround the volcano; the youngest were dated at about 2,000 years BP. A report stated that Matutum was "smoking" on 7 March 1911 (Neumann van Padang, 1953). The Akmoan and Lianan thermal areas are located on the WSW flank of the volcano.