Mount Tondano

Mount Tondano in the province of North Sulawesi, Sulawesi, Indonesia, has a 20 × 30 km wide caldera which was formed in the Late Miocene or Early Pliocene by a massive eruption. Post caldera activity includes pyroclastic cones, obsidian flows and geothermal areas in the caldera area. Lake Tondano lies in the east side of the caldera.