Laguna del Diamante

Laguna del Diamante in Mendoza Province sits at 3,300 metres in a volcanic amphitheatre directly beneath the Maipo volcano, and the lake's extraordinary colour — an electric blue produced by dissolved minerals from the geothermal activity beneath it — makes it look like an artificially coloured film set rather than a natural body of water. The drive from the Mendoza valley climbs 3,000 metres in 90 kilometres through a landscape that passes from vineyard to mountain desert to high Andean plateau to volcanic moonscape without warning. Flamingos feed in the shallows.

Laguna del Diamante is a volcanic crater lake in the Laguna del Diamante Provincial Reserve, formed in the caldera of the Diamante volcano and fed by meltwater from the adjacent Maipo volcano (4,004 metres), which remains volcanically active and contains a summit fumarole field. The lake sits at the southern end of the Tupungato-Maipo volcanic complex, one of the most volcanically active sections of the central Andes, and its distinctive colour results from the high concentrations of arsenic, boron, and sulphur dissolved from the volcanic substrate. The extreme conditions of the lake — high altitude, high UV radiation, extreme temperature variation, and volcanic chemistry — support extremophile microbial communities similar to those proposed as analogues for potential life on other planets. Access is via a 90-kilometre dirt road from San Rafael that is closed by snow between April and November.