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Dominica’s preeminent trek, and one of its hardest, travels 4 miles to a 207ft-wide boiling lake, which is actually a flooded fumarole – a crack in the earth that allows hot gases to vent from the molten lava below. Take the trailhead at Ti Tou Gorge and budget no less than six hours for the round-trip.

While the largest such lake is found in New Zealand, this is the hottest, although the temperature is not constant, and the lake sometimes goes 'dry' (the local phrase for when the water is normal temperature). All hikers should hike with an experienced guide (about US$50 per person, more with car transfer).