The narrow basalt corridor of Titou Gorge was carved over millennia by geothermal runoff from the Morne Watt caldera, its walls rising thirty metres above a channel barely three metres wide in places. The gorge sits at 580 metres elevation in the southern quadrant of Morne Trois Pitons National Park, a 6,857-hectare UNESCO World Heritage Site gazetted in 1975 and inscribed in 1997 for its concentration of volcanic features — fumaroles, hot springs, freshwater lakes, and five distinct vegetation zones compressed into a single watershed. The site gained international attention in 2006 when its moss-hung entrance and slot-canyon interior appeared in a major motion picture, but the gorge had been a known bathing site among Laudat villagers since the mid-nineteenth century, who used the thermally warmed pools as a respite after mountain cultivation work. Today the titou gorge excursion anchors the park's northern access zone, drawing visitors who arrive by minibus along the Laudat Road from Roseau, a twenty-five-minute drive through banana groves and secondary rainforest. The swim begins at a cobblestone entry pool where the Titou River emerges from the gorge mouth, fed by cold tributary streams mixing with geothermal seepage that raises the water temperature to a steady 24°C. The route demands a hundred-metre swim against a gentle current, punctuated by short wading sections where submerged boulders allow footing. Algae-slicked walls lean inward, filtering midday light into a blue-grey dusk broken only by shafts that angle through crevices in the basalt cap. Tree ferns and wild ginger root down from ledges ten metres overhead, their fronds trailing into the water. The channel dead-ends at a five-metre cascade fed by the same hydrothermal system that supplies the Boiling Lake, three kilometres southeast along the ridge. The waterfall plunges from a fissure in the gorge roof, its spray rebounding off a rear wall worn smooth by centuries of erosion. Marine geologists have documented the basalt here as part of the Morne Trois Pitons Formation, dated to the late Pleistocene and linked to the same magma chamber that drives the Valley of Desolation fumarole field. The gorge remains the most accessible swim-through slot canyon in the Lesser Antilles, its combination of navigable depth, thermal modification, and intact riparian canopy unmatched elsewhere in the Windward Islands volcanic arc.