16 Geosites within the Toba Caldera Geopark

A total of 16 geosites within the Toba Caldera Geopark (TCG) has served as the key natural heritage on Lake Toba. The term “geosite” refers to sites that get recognized as essential elements of the park. Some of these locations have been on the list because they provide opportunities to experience the relationship between geology and history, culture, or daily life, as well as for their geological or topographical characteristics.

Visiting them is an excellent way to learn more about the geology, history, and culture of the park.

1. Sibaganding Geosite

Sibaganding Geosite represents a Mesozoic-aged limestone (840,000 years old) in the form of rocks located at Porsea Geoarea. The landscape lies on the eastern shore of Lake Toba (Parapat, Simalungun) and is composed of limestone pack-stone, glauconitic grainstone, and rock-and-tone sandstone. The formation includes a stone that looks like a human posture in the upside down position. The residents call it Hanging Stone. To see what you can do and how to get there, click here.

2. Garden of Eden 100 Geosite

Garden of Eden 100 Geosite is the outcrop of the mudstone (metasediment) unit exposed on a waterfall cliff and aged 840,000 years at Porsea Geoarea. This geosite is in Lumban Rang Village, North Sionggang, Lumban Julu District, Toba Samosir, 1,100-1,750 meters (3,600-5,700) above sea level. The Garden of Eden 100 is also a nature park with a mission to preserve the forest around Lake Toba. To see what you can do and how to get there, click here.

3. Basiha Stone-TB Silalahi Geosite

Basiha Stone is a collection of andesite rocks of horizontal columns (larger than 30 cm in size) in Toba Samosir, which characterizes the giant dike structure. Basiha Stone is known as rocks with stacked columns of cooling magma as it flew and froze on the surface forming lava columns when Mount Toba erupted 840,000 years ago (first eruption). To see it on the map, click here. It is near TB Silalahi Batak Museum that houses similar objects of earth heritage. To see what you can do at this museum and how to get there, click here.

4. Situmurun Geosite

Situmurun Geosite in Toba Samosir is the biggest and most beautiful among the waterfalls that descend directly onto Lake Toba. Similar to No. 1 to No. 3, the cliffs are in the Porsea Geoarea. They appeared as a result of a massive volcanic eruption that happened some 840,000 years ago. The waterfall is not reachable by land road, so hire a boat from Parapat if you want to get there. To see what you can do at this waterfall, click here.

5. Sipiso-piso Geosite

Sipiso-piso Geosite in Karo (Haranggaol Geoarea) includes the volcanic cone mount of Sipiso-piso, which is the result of a post-Youngest Toba Tuff (YTT) volcanic activity during the 2nd eruption (501,000 years ago), showing the andesite larvae with burning contact with the core rock consisting of the YTT deposits. This mountain is unique. Trees can grow there at the summit only. There is a refreshing waterfall near the mountain. To see what you can do and how to get there, click here.

6. Silahi Sabungan Geosite

Silahi Sabungan Geosite in a district in Dairi. It represents a beach and mountain area that keep traces of the major eruption taking place 501,000 years ago. Visit Paropo or Silalahi Beach to touch the rocks spewed out by the volcano while enjoying the cool weather and the lake panorama from its northern tip. Silalahi Beach offers clear water as well. The water clarity allows you to see fish and the rocks deep down in the lake. To see what else you can do and how to get there, click Paropo and Silalahi Beach.

7. Haranggaol Geosite

Haranggaol Geosite includes a caldera wall showing the YTT pyroclastic flow exposed on the cliff of Haranggaol, Simalungun. This sediment did not undergo welding during the 2nd eruption 501,000 years ago. There is also a cave on the edge of the lake that was once a vacation spot for the Batak kings. Residents call it Grand Canyon of Indonesia. To see what you can do and how to get there, click here.

8. Huta Ginjang Geosite

Huta Ginjang Geosite is a beautiful area on the southern shore of Lake Toba at Sibandang Goearea in North Tapanuli. The landscape emerged as the result of the 3rd eruption of Mount Toba 74,000 years ago. Its height, proximity to the airport and panorama have made Huta Ginjang an ideal location for visitors who like to rush to see the lake upon arrival. To see what you can do and how to get there, click here.

9. Muara Sibandang Geosite

Muara Sibandang Geosite represents two connected landscapes in North Tapanuli. Muara is the beach that overlooks Lake Toba from the south shore. Sibandang is the 2nd largest island inside the lake (after Samosir island). Unlike the shores of Lake Toba and Samosir which are familiar with sandy beaches, Sibandang’s and Muara’s shores are mostly rocks. The stones survive the world’s largest volcanic eruption that took place 74,000 years ago. To see what you can do and how to get there, click here.

10. Sipinsur Geosite

Sipinsur Geosite is a beautiful hill located on the south shore of Lake Toba in Humbahas, formed as the result of the powerful volcanic eruption 74,000 years ago. When standing on the edge of the hill, you can see a much bigger picture of the lake than what you can see elsewhere in general, given that your position is 1,213 meters (3,980 ft) above sea level. To see what you can do and how to get there, click here.

11. Bakkara Tipang Geosite

Bakkara-Tipang Geosite is a landscape located within Sibandang Goearea and covers Bakkara and Tipang villages in the Baktiraja District in Humbahas. The area was shaped following the 3rd eruption 74,000 years ago. The geosite is home to attractions such as Sisingamangaraja PalaceBakkara ValleyJanji WaterfallAek Sipangolu, and Tipang. To see what you can do there, click on any of the relevant blue text in this paragraph.

12. Tele Geosite

Tele Geosite consists of Panatapan, Simanukmanuk, Simpang Gonting and Simpang Limbong geopoints. The geosite is located in Sumatra but still within the Samosir Regency, and within Samosir Geoarea. Scientists have noted that rocks and sediments at those geopoints evidence the uplifting of Samosir island as the result of the local tectonic activity around 33,000 years ago. To see what you can do and how to get there, click here.

13. Pusuk Buhit Geosite

Pusuk Buhit Geosite consists of Mount Pusuk BuhitPangururan Thermal Bath, Hobon Stone, Sigulanti Village (Sianjur Mulamula), Aek Sipitu Dai and other springs in the area, Tano Ponggol (the land connecting Sumatra with Samosir island), and Sawan Stone. The geosite is within the Samosir Geoarea that took shape around 33,000 years ago. To see what you can do there, click on any of the relevant blue text in this paragraph.

14. Hutatinggi Sodihoni Geosite

Hutatinggi Sidihoni Geosite is a 105-hectare (260 ac) lake located around 1,300 meters (4,265 ft) above sea level on Samosir Island within Lake Toba. The “lake on the lake” lies above lake sediments that were formed during the uplifting of the island and formation of the basin as a result of the local faults due to the tectonic activity around 33,000 years ago. There are also smaller lakes on Samosir island, i.e., Lake Aek Natonang and Lake Aek Parohan. To see what you can do and how to get there, click here.

15. Ambarita-Tuktuk-Tomok Geosite

Ambarita-Tuktuk-Tomok Geosite covers the areas of Ambarita, Tuktuk and Tomok on Samosir, which are famous for the numerous megalithic objects, e.g., Stone Chairs of King Siallagan, Tomb of King Sidabutar, and artifacts kept in the Huta Bolon Simanindo Museum. The areas emerged through the uplifting of lake sediments as the result of the tectonic activity around 33,000 years ago. To see what you can do there, click on any of the relevant blue text in this paragraph.

16. Lake Toba

Lake Toba Geosite is the unifying geosite within the TCG. The series of volcanic eruptions with the last one taking place 74,000 years ago left a large caldera that was later filled in with 240 cubic kilometers (57.6 cu mi) of water. The lake was born, and a new life began. The blue water and green vegetation of the lake have attracted inhabitants as well as tourists. Come and enjoy the stunning beauty of the lake and the distinctive culture of its inhabitants (see People and Culture on Lake Toba).

See also Flora on Lake Toba.