Lake Toba is also included in the list of world wonders located in North Sumatra Province, Indonesia .. Lake Toba is a volcanic lake are thought to have formed as a result of the eruption of one of the ancient mountain, Mount Toba, which occurred at 73000-75000 years ago. The blast also be the biggest explosion called a super volcano eruptions and made a number of species experiencing mass death and extinction. Even more than 60 million people estimated to have died during the incident. As a result of the eruption, the caldera formed a fairly wide which then fills with water to form a lake that is now known as Lake Toba. While a small island located in the middle of Lake Toba, which is called by the name of Samosir Island, caused by pressure of magma that has not come out. Lake Toba is above 900 meters above sea level, making the air temperature in the lake sekitara also pretty cool. Lake Toba is also quite spacious with a length of 100 km and a width of 30 km. While it's depth ...