A salt cave, in a paleo-salar, near Tolar Grande, on the Altiplano (Puna) of Salta, Argentina

A salt stalactite, inside a salt cave, in a paleo-salar, near Tolar Grande, on the Altiplano (Puna) of Salta, Argentina

Sand dunes, Catamarca, Argentina

Sedimentary rocks in the Labyrinth Desert, province of Salta, Argentina

Tourists exploring a basalt flow, near Antofagasta de la Sierra, province of Catamarca, Argentina

Volcanic bombs, province of Jujuy, on the Andean Altiplano, Argentina

Volcanic bombs, near the town of Susques, province of Jujuy, Argentina

Volcanic landscape near El Peñón, on the Altiplano (Puna) of Catamarca, Argentina

'Young' volcano, on the Altiplano of Catamarca, Argentina

Young volcano, lava flow, the Carachipampa lagoon, on the Altiplano of Catamarca, Argentina

Young volcano, lava flow, near Antofagasta de la Sierra, on the Altiplano (Puna) of Catamarca, Argentina

Chemical rocks, geysers El Tatio, Chile, Andean Altiplano (high plateau), the Andes Cordillera

Chemical rocks, geysers El Tatio, Chile, Andean Altiplano (high plateau), the Andes Cordillera

The Atacama Salar (salt flat), in the Atacama Desert, Chile

The Salt Cordillera, in the Atacama Desert, Chile

Detail of rocks in the Salt Cordillera, in the Atacama Desert, Chile