Salar de Uyuni
This 9,000 km (4680 sq mi) salt desert at an altitude of 3650m (11,970ft), is the largest salt flat in the world! It was once part of a prehistoric salt lake which covered most of southwestern Bolivia. Armed with only picks and shovels, the local campesinos harvest salt from this ancient lake filled with an estimated 10 billion tons of fine salt.
Situated in a semi-arid climate, the Salar has an average annual rainfall of about 10 inches. If you take a tour of Salar during the rainy season, from December to March, it may be covered with salt water to depths of 25 cm; however during the dry season, the salt water evaporates to a layer above or below the surface.