Salar de Uyuni (Potosí and Oruro departments, Bolivia)

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 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. The Salar also contains large amounts of sodium, potassium, magnesium and borax.