Remote Niuafo’ou, about 100km west of Niuatoputapu, looks like a huge doughnut floating in the ocean. But it's not fast food for giants – it's a collapsed volcanic cone (caldera), thought to have once topped 1300m in height. Today, the highest point on the caldera is 210m, and the lake it encloses is nearly 5km wide and 23m above sea level.
During the past 150 years, Niuafo’ou has experienced 10 major volcanic eruptions. After a particularly nasty one in 1946, the government evacuated the 1300 residents to ‘Eua island, and Niuafo’ou was uninhabited until 200 homesick locals returned in 1957.
Niuafo’ou has no coral reef and no sandy beaches, just open ocean surrounds. A track leads right around the caldera and its impressive freshwater lake, Vai Lahi (Big Lake). Keep an eye out for Niuafo’ou’s most unusual inhabitant, the turkeylike Tongan megapode, which uses the warm volcanic soil to incubate its eggs. Efforts to save this threatened bird have included transplanting chicks to the uninhabited volcanic islands of Late and Fonualei, two of Vava’u’s outlying islands.
Real Tonga lands on Niuafo'ou Airport's grassy strip, winging in from Vava'u. There are a few campsites on the crater, although you should ask for permission from locals first. A handful of village houses offer guest rooms; contact the Nuku'alofa Visitor Information Centre in Tongatapu for details. There are several small shops scattered through the villages, but bring plenty of food and cash with you (no ATMs).