The Cordillera de la Sal is located between the eastern flank of the 700 km long Cordillera de Domeyko and the western flank of the Cordillera de Los Andes. These mountains were formed at the bottom of a large inland sea, during the last 2 million years, thanks to the activity of the tectonic plates located under the earth's crust. Their surface is covered with white salt crystals.

Next to the Cordillera de la Sal and 15 minutes from San Pedro, you can find the Valle de la Muerte and Valle de la Luna, two geological sites of great tourist interest.

Death Valley is an area surrounded by eroded cliffs, small hills, and sand dunes. Some of them rise over 100 meters high, which is why sandboarding is so popular in this area.

 

The Valley of the Moon, located 15 kilometers northwest of San Pedro, is a small valley of about 500 meters, at an altitude of 2,624 meters above sea level, surrounded by impressive cliffs with jagged ridges. The Valley of the Moon is a well-known place to watch the sunset, for which visitors climb a 100-meter dune, from where they can enjoy a great view of the cliffs. The ground surface has mineral salt crusts, and the surrounding hills also have a high salt content, which captures the blue of the evening sky and reflects it across the valley. Carnegie Mellon University's Robotics Institute and NASA conducted a series of tests of the new Nomad lunar rover at this site in 1997.

 
The special geology of the mountain range and the valleys are the result of deep transformations of the earth's crust, produced by successive folding of the lake bed of the Salar de Atacama. In addition to the high saline content, rock formations of various shapes comprise layers of chlorate, borate, calcium, and clay.