There is a particular kind of alarm clock that only makes sense on holiday: the 2am wake-up call for a volcano sunrise. Bleary-eyed and slightly disbelieving, we set off through the dark Balinese countryside towards Mount Batur, one of the island’s most recognisable landmarks and, as it turns out, a rather more geologically interesting one…

There’s a version of Bali most people never see, and it sits about two hours northeast of the terraced rice fields and beach clubs, at the edge of a volcanic lake inside a crater most tourists photograph from a distance and never actually enter. Trunyan is a village on the eastern shore of Lake Batur,…