Mount Apo is a large stratovolcano on the island of Mindanao in the Philippines. It is the highest mountain in the country and overlooks Davao City, a few kilometres to the northeast. Its name means "master" or "grandfather". Apo is flat topped, with three peaks, and is capped by a 500 m wide volcanic crater containing a small crater lake. It is a source of geothermal energy, but the date of its most recent eruption is unknown, and none are verified in historic times.