Calbuco (kahl-BOO-koh; Spanish: Volcán Calbuco, pronounced: [bolˈkaŋ kalˈβuko]) is a stratovolcano in southern Chile, located southeast of Llanquihue Lake and northwest of Chapo Lake, in the Los Lagos Region. The volcano and the surrounding area are protected within Llanquihue National Reserve. It is a very explosive andesite volcano whose lavas usually contain 55 to 60% silicon dioxide (SiO₂).