Sala de Uyuni is the worlds largest salt flat at 4,086 square miles. Located in the Daniel Campos Province in Potosi in southwest Bolivia near the crest of the Andes, the Salar was formed as a result of transformations between several prehistoric lakes. It is covered by a few meters of salt crust, which is completely flat with the average elevation being within one meter over the entire area of the flat. The salt crust covers a pool of brine, which is rich in lithium. The large area, clear skies, and flatness of the surface makes the Salar an ideal object for calibrating the altimeters of Earth’s observation satellites.