Río Chollín (Rivière Chaude)

Río Chollín (Rivière Chaude) near La Fortuna, Costa Rica, is a silica-rich geothermally heated river where volcanic heat from Arenal's hydrothermal system warms a natural watercourse flowing through tropical rainforest, creating informal bathing conditions along a wild riverbank without constructed pool infrastructure. The siliceous mineral content of the water, derived from volcanic rock dissolution, gives the river a characteristic smoothness appreciated by bathers. The experience of soaking in a naturally warm jungle river while surrounded by rainforest vegetation, with the sounds of birds and flowing water as the only soundtrack, represents one of the most elemental and unmediated geothermal bathing experiences available in Costa Rica's volcanically active La Fortuna region.