Danau Toba has been part of traveller folklore for decades. This grand ocean-blue lake, found up among Sumatra’s volcanic peaks, is where the amiable Christian Batak people reside. The secret of this almost mythical place was opened up by intrepid travellers years ago. While these days Tuk Tuk – the knobby village on the lake’s inner island – is on the beaten Sumatran overland path, it's still one of the undisputed highlights of central Sumatra.
Danau Toba is the largest lake in Southeast Asia, covering a massive 1707 sq km. In the middle of this huge expanse is Pulau Samosir, a wedge-shaped island almost as big as Singapore that was created by an eruption between 30,000 and 75,000 years ago. In fact, Samosir isn’t actually an island at all. It’s linked to the mainland by a narrow isthmus at the town of Pangururan – and then cut again by a canal.