Morne Trois Pitons

Declared in 1975 — Dominica's first national park — and a UNESCO World Heritage Site since 1997, the first natural site in the whole Lesser Antillean chain to be so recognised, Morne Trois Pitons combines all but virgin rainforest with intense geothermal activity, including the Boiling Lake, the second largest boiling lake in the world after one in New Zealand, formed over an active volcanic fumarole that keeps its grey water at a near-constant boil at between 82 and 91°C.