It is at the end of 90km of track through the Chilean Altiplano from San Pedro de Atacama that the site of the geysers of El Tatio is located. This geothermal zone, the most important in the southern hemisphere, hosts 80 active geysers at 4230m altitude. It is at daybreak, thanks to the difference in temperature, that the geysers become active. The plumes of sulphurous vapours then cast their ghostly shadows on the ground.