Danau Toba or Toba Lake is one of the most popular destinations in Indonesia, especially in Medan, North Sumatra. Danau Toba is the largest volcanic lake in Indonesia, even in the Southeast Asia. Which make it more special is taken from the Samosir Island, an Island that settled in the middle of the lake.
Lake Toba is an area of 1,707 km², we can say that this is 1,000 km² bigger than Singapore. It formed by a gigantic volcanic eruption some 70,000 years ago, it is probably the largest resurgent caldera on Earth. Pulau Samosir or Samosir Island, The island in the middle, was joined to the caldera wall by a narrow isthmus, which was cut through to enable boats to pass; a road bridge crosses the cutting. Samosir island is the cultural centre of the Batak tribe, the indigenous from North Sumatra.
By the eruption of a super volcano (Mount Toba) was estimated to have caused mass death and extinction of several species of living creatures. The eruption of Mount Toba has led to changes in the earth’s weather and the start into the ice age that affects the world civilization.
Lake Toba is actually more like a sea than a lake considering its size. Therefore, the Lake placed as the largest lake in Southeast Asia and the second largest in the world after Lake Victoria in Africa. Lake Toba is also includes the deepest lake in the world, which is approximately 450 meters.
more info : http://www.indonesia-tourism.com/north-sumatra/toba_lake.html