Location Geopark Lake Toba become a mainstay attractions in Samosir regency, North Sumatra, centered in the Village Sigulatti, District Sianjur Mulamula.
Lake Toba as the largest volcanic lake in Southeast Asia is an interesting object because of its natural beauty equipped with cultural richness and is considered as the origin of ancestral Batak tribe.
Called as Toba Geopark not because Batak Toba or Toba Lake, but because of the wealth and geological potential in the lake area located in the central part of North Sumatra Province covers seven districts.
There are 42 geosite for Geopark Toba divided into four geo areas, namely:
1. Haranggaol Caldera,
3. Sibandang Caldera
4. Geo Area of Samosir Island.
Combined from Geo Area it is called as Geopark. For the District of Samosir built as many as eight panels (signage) for eight geosite.
Geopark’s location is managed to be a tourism object with three aspects of management covering conservation, education (education, geological science, biology and culture research) as well as aspects of local economic value development through sustainable tourism activities.
Lake Toba is the largest caldera lake in the world located in North Sumatra Province, 176 km to the west of Medan City. Lake Toba (2.88o N – 98,5o 2 E and 2,35o N – 99,1o E) is the largest lake in Indonesia (90 x 30 km2) and is also a volcano-tectonic caldera (giant volcanic crater) largest quarter in this world. The caldera is formed by the post-eruption process of post-eruption supervolcanogunungapi Toba Purba, then filled by rain water.
Lake Toba has a length of 87 km northeast-southeast with a width of 27 km with an altitude of 904 meters above sea level (asl) and the depth of the deepest lake 505 meters. In the middle of Lake Toba Samosir Island is located with altitudes ranging between 900 to 1,600 meters above sea level, which is formed due to the removal of the lake base post-eruption caldera that occurred 74,000 years ago, as the end of the process of achieving a new equilibrium post-eruption caldera supervolcano.
Toba Caldera wall area has the morphology of rugged hills to steep and valleys form the morphology of the terrain with the limit of caldera rim watershed DTA Lake Toba with the area of catchment area (3,658 km ²) and the surface area of the lake is 1.103 km ². This catchment area is hilly (43%), mountain (30%) with peak of 2,000 meters above sea level (27%) as a place for community activity.
In relation to its uniqueness, Toba Caldera is proposed to be a geopark with the name Geopark Caldera Toba (GKT). To realize the desire, formed the Team Acceleration Filing Geopark Caldera Toba become a member in Global Geopark Networking UNESCO, by issuing the Decree of the Governor of North Sumatra. 188.44 / 404 / KPTS / 2013 on June 26, 2013.
Initially, in 2011 the name of geopark was proposed by the name of Geopark Toba, but in its development considering that the world heritage worth is a relic of the super volcano Toba eruption that has a global impact of Lake Toba which is none other than the largest Quaternary Caldera in the world, it proposed the name of geopark in 2013 with the name Geopark Caldera Toba.
Geopark Toba Caldera carries the Volcano theme (supervolcano) with the uniqueness as the largest Quarter Volcano-Ttone Caldera in the world. This area covers part of the administrative area of seven districts that have beaches in Lake Toba which are limited by the caldera rim ie Samosir District, Toba Samosir Regency, Dairi Regency, Karo Regency, Humbang Hasundutan Regency, North Tapanuli Regency and Simalungun Regency.