Gaua

At Gaua's centre, Lake Letas bends in a U around the cone of Mount Garet, dark water against a mountain that still smokes. The lake's overflow runs east through jungle and drops 120 metres as Siri, Vanuatu's highest waterfall. One small island holds the whole system: lake, volcano, fall.

Lake Letas is Vanuatu's largest lake, nine kilometres long and six wide, wrapping Mount Garet on every side but one; the cone within it is an active stratovolcano with three summit pit craters, and access follows the volcanic alert system, so the guide decides where any given day can go. The trekking is genuinely earned. Accredited local guides lead routes short and long that cross gardens and coconut plantations on hand-macheted jungle paths, canoe the lake, camp on its shore and finish at Siri, whose 120-metre drop carries the lake's overflow to the coast. Gaua holds a second wonder that has nothing to do with geology: this is a home of Vanuatu's women's water music, performers standing waist-deep and striking, plunging and ploughing the surface until the sea itself becomes the drum, an art refined by generations of Banks Islands women.