Female tourist on Salar de Uyuni during sunset, Altiplano Bolivia - Stockfoto

Salar de Uyuni (or Salar de Tunupa) is the world's largest salt flat at 10,582 square kilometers (4,086 sq mi). It is located in the Potosi and Oruro departments in southwest Bolivia, near the crest of the Andes, and is elevated 3,656 meters above the mean sea level. The Salar was formed as a result of transformations between several prehistoric lakes. It is covered by a few meters of salt crust, which has an extraordinary flatness with the average altitude variations within one meter over the entire area of the Salar. The crust serves as a source of salt and covers a pool of brine, which is exceptionally rich in lithium. It contains 50 to 70% of the world's lithium reserves, which has yet to be extracted.