As a caldera formed by the eruption of a supervolcano, Lake Toba is surrounded by interesting geological formations. One of these is Sipiso-piso waterfall, which translates literally as “like a knife.” An underground river that runs along the Karo Plateau comes to a sudden 390-foot plunge before joining the waters of the lake. Water pours out of an opening in the cliff as if it had just broken through it. Sipiso-piso is located in the hills, at an altitude of about 2,600 feet above sea level. The land surrounding the…
