Lake Toba is a large lake, 100 km long and 30 km wide, in the middle of the northern part of the Indonesian island of Sumatra, Indonesia. When you see it you will probably be amazed of its natural beauty and lovely landscapes, but do not forget how it was formed in the past. The enormous inland lake has a history spoken of in local myths, but the true story of Toba and how this enormous inland lake evolved, lies in knowing the story of its Toba volcano.

In 1949 the Dutch geologist Rein van Bemmelen reported that Lake Toba was surrounded by a layer of ignimbrite rocks, and that it was a large volcanic caldera. Later researchers found rhyolite ash similar to that in the ignimbrite around Toba (now called Young Toba Tuff to distinguish it from layers deposited in previous explosions) in Malaysia and India, 3000 km away. Oceanographers discovered Toba ash, with its characteristic chemical “fingerprint”, on the floor of the eastern Indian Ocean and the Bay of Bengal.

The Toba eruption occurred at what is now Lake Toba about 75 000 years ago. It had an estimated Volcanic Explosivity Index of 8 (which is known as mega-colossal), making it possibly the largest volcanic eruption within the last two million years. According to the researches made by Bill Rose and Craig Chesner of Michigan Technological University the total amount of erupted material was about 2800 cubic km (670 cubic miles) — around 2000 cubic kilometres of ignimbrite that flowed over the ground and around 800 cubic kilometres that fell as ash, with the wind blowing most of it to the west. By contrast, the 1980 eruption of Mount St. Helens in United States ejected around 1 cubic km of material, whilst the largest volcanic eruption in historic times, at Mount Tambora in 1815, emitted the equivalent of around 100 cubic kilometres of dense rock and created the “Year Without a Summer” as far away as North America.

To give an idea of its magnitude, consider that although the eruption took place in Indonesia, it deposited an ash layer approximately 15 cm (6 in) thick over the entire Indian subcontinent; at one site in central India, the Toba ash layer today is up to 6 m (20 feet) thick and parts of Malaysia were covered with 9 m of ashfall. In addition it has been calculated that an amount of 1010 metric tons of sulphuric acid was ejected into the atmosphere by the event, causing acid rain fallout.

The subsequent collapse formed a caldera that, after filling with water, created Lake Toba. The island in the southern part of the lake is formed by a resurgent volcanic dome.

The Lake Toba is definetely a place to visit if you are in Indonesia. The main nearest to the lake town is Parapat, which is about 4 hours by car from Medan (4-6 hours by public bus). Local transportation around the lake takes the form of boats (cheaper, school boats with limited schedules and more expensive public boats that operate throughout the day). You can also hire a motorcycle for a day or two and get out and about (Rp.50,0000 per day inclusive of 4 litres of petrol). There are no police checking licences and there is not much traffic – just watch out for the big trucks, buses and diabolical bridges. A good journey to take on a motorcycle would be to travel North from Tuk Tuk around to the western shore, stopping at the tourist sites along the way such as the many and varied traditional houses. Motorcycles are almost always semi-automatic meaning there is no need to use a clutch to change the foot-operated gears.

Tabo Cottages is the most luxurious accommodation on the island. Prices start at around Rp.120,000 per night and climb up from there. The rooms are very clean and quite modern by Sumateran standards. Internet is available from the family’s computer for a nominal rate and the western-styled food served in the restaurant is very good.

You can eat at Jenny’s Restaurant on Samosir Island, Tuk Tuk. There is only one or two roads in Tuk Tuk, so simply ask for Jenny’s. Jenny and her husband Rinto run the very simple but cozy restaurant with view on the wonderful lake Toba. You will notice that every day the table cloth are being changed, a usually rare to find nicety and convenience. The curry is delicious. A must-try is the fresh lake-fish, steamed or grilled. Even western food like Schnitzel (breaded pork or chicken chop pan fried) is very good. For dessert try the fresh papaya that grows in the back-yard or a golden-brown banana pancake with chocolate sauce and a sprinkle of coconut. Once all the guests in the small place with only about 5 tables are fed and happy, Rinto will take the guitar from the wall and entertain his patrons. When he is singing old Batak songs about earlier times and you listen to the guitar tunes and his melancholic voice, your eyes wander over the lake and you feel like never leaving Samosir again.

A journey to Lake Toba will be definetely a great travel exprerience for you!