Distance: 200 km. (total round trip)
It is necessary to leave very early in the morning to get close to sunrise and to be able to observe a unique spectacle.
It is the third largest Geothermal Field in the world after those of the Yellow Stones National Park in the United States and those of the Kronótskaya Nature Reserve on the Kamchtka Peninsula, Russia.
The geothermal field is made up of around 40 geysers (boiling water at 85 ° C due to the elevation), 70 fumaroles (only steam) and 50 hot springs (very hot water, not suitable for bathing)
The water of the geysers runs down the hill, forming the origin of the Salado River which, after descending through gorges, flows into the Loa River.
Thermophilic bacteria: these bacteria resist extreme temperatures; high and very low temperatures (in winters of 2005 and 2006 there have been down to -31 ° C