Indonesia contains Lake Toba, the world’s largest volcanic lake by surface area.
Lake Toba occupies the caldera of a gigantic supervolcano in North Sumatra. The eruption that formed the caldera occurred about 74,000 years ago and is regarded as one of the largest known explosive eruptions in Earth’s recent geological history.
The lake is about 100 kilometres long and 30 kilometres wide. Samosir Island rises in its centre and is connected to the surrounding land by a narrow isthmus. The area is closely associated with the Batak peoples and their distinctive cultural traditions.
Lake Toba is sometimes called simply a crater lake, but its exceptional size comes from a huge volcanic caldera rather than an ordinary small volcanic crater.