Osorno volcano is a symmetrical, glacier-covered stratovolcano in southern Chile, rising above Todos los Santos and Llanquihué lakes.
Osorno is one of the most active volcanoes of Chile. Historical eruptions have often produced produced lava flows. Many eruptions have occurred from both summit and flank vents and fissures, the latter mostly on the west and SW sides. Lava flows from its eruptions have reached Todos los Santos and Llanquihué lakes.
While its historic activity was dominantly effusive, many explosive eruptions which generated pyroclastic flows and surges have been identified to have occurred during the past 14,000 years.