A flooded volcanic vent keeps an entire lake at a rolling boil

The Boiling Lake in Dominica sits inside Morne Trois Pitons National Park, a flooded fumarole where volcanic gas and heat vent up through a crack in the Earth, keeping the lake's grey-blue water in constant, roiling motion and usually shrouded in steam. At roughly 60 metres across, it's typically cited as the second-largest boiling lake on Earth, after one in New Zealand.

— UNESCO World Heritage Centre, Morne Trois Pitons National Park — World Heritage List, inscribed 1997