Uyuni Termas Polques

Termas de Polques in Bolivia's Eduardo Avaroa Andean Fauna National Reserve is one of the most surreal thermal experiences on Earth — a natural hot spring at 4,400 metres altitude, where visitors bathe in 29°C waters while surrounded by snow-capped volcanoes, flamingo-populated salt lakes and the vast desolation of the Altiplano. The sodium bicarbonate waters emerge from geothermal vents fed by the volcanic activity of the Andes, and the spring sits within metres of Laguna Polques, whose shallow alkaline waters are bright pink with flamingos. Reaching Polques requires traversing the extreme landscapes of the Bolivian Lipez, typically as part of a jeep tour from Uyuni. The combination of altitude, volcanic geology and Andean wilderness makes this one of the world's most memorable thermal bathing spots.