This Envisat image features salt flats in the Department of Potosi in southwest Bolivia, near the crest of the Andes Mountains. The Salar de Uyuni (the lower white area) is the largest salt flat in the world, occupying 10 582 sq km. It is located at the southern end of the Altiplano, a high plain of inland drainage in the central Andes. Some 40 000 years ago, this area was part of a giant prehistoric lake that dried out, leaving behind two salt flats, the Uyuni and the Salar de Coipasa (visible above Uyuni), as well as two modern lakes, Poopó (visible in green) and Uru Uru. Occupying 2218 sq km, Salar de Coipasa is Bolivia's second largest salt flat. Stretching 90 km in length and 32 km in width, Lake Poopó is the country's second largest lake with the permanent part of its body covering approximately 1000 sq km. This image was acquired by Envisat’s Medium Resolution Imaging Spectrometer (MERIS) instrument on 7 May 2008 working in Full Resolution mode to provide a spatial resolution of 300 m.