Lake Toba is both a body of water and super volcano. The lake, which sits in a crater, was formed between 69,000 and 77,000 years ago and is believed to have been the result of a catastrophic eruption. The lake is 1,145 square kilometers and 450 meters deep. Volcanic activity is still regularly recorded here and has pushed some islands above the water's surface. Lake Toba is a study in beauty and the powerful forces at work on the planet. Here, you can go swimming, water skiing, canoeing, or fishing, or stick to wandering the surrounding area on foot or bike.