Lake Toba (Indonesian: Danau Toba) is a large natural lake in North Sumatra, Indonesia, occupying the caldera of a supervolcano. The lake is located in the middle of the northern part of the island of Sumatra. It is the largest lake in Indonesia and the largest volcanic lake in the world. Toba Caldera is one of twenty Geoparks in Indonesia, and was recognised in July 2020 as one of the UNESCO Global Geoparks.