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 elevation 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 known lithium reserves, which is in the process of being extracted.

The large area, clear skies, and exceptional flatness of the surface make the Salar an ideal object for calibrating the altimetersof Earth observation satellites. The Salar serves as the major transport route across the Bolivian Altiplano and is a major breeding ground for several species of flamingos. Salar de Uyuni is also a climatological transitional zone since the towering tropical cumulus congestus and cumulominbus incus  clouds that form in the eastern part of the salt flat during the summer cannot permeate beyond its drier western edges, near the Chilean border and the Atacama Desert.

Salar de Uyuni was the shooting location for a major battle scene in Disney’s blockbuster 2017 movie Star Wars: The Last Jedi, representing the planet Crait.