The hook
An enormous lake filling the crater of one of the largest volcanic eruptions in the history of the planet, with an island nearly the size of Singapore sitting in the middle of it, home to the Batak people.
01Why it's worth it
Lake Toba sits in the caldera left by a colossal supervolcanic eruption around 74,000 years ago, one of the largest known, so violent that some scientists think it briefly cooled the whole planet and squeezed early humanity through a bottleneck. What remains is serene: a vast, deep, blue highland lake, cool and calm, with the large island of Samosir rising in its centre. Samosir is the heartland of the Batak, whose distinctive boat-shaped houses, carved tombs, and traditions give the lake its culture, and it has long been a laid-back travellers' retreat of lakeside guesthouses. After the heat and hassle of lowland Sumatra, Toba is a place to slow right down: swim, ride a scooter around the island, and take in the villages and the water. It is more about calm and depth of time than dramatic sights.
02How to experience it
Cross to Samosir island and settle in for several unhurried days: swim, scooter around the shore, and visit the Batak villages, king's tombs, and traditional houses. Enjoy the cool highland air. It rewards slowing down rather than ticking off sights.