The World's Largest Salt Lake

Salar de Uyuni (Uyuni Salt Flat) is the world’s largest salt lake, and is without doubt one of the most fascinating and beautiful places to discover in Bolivia and South America. The salt flat is roughly 25 times the size of the Bonneville Salt Flats in the United States, and is estimated to hold nearly 10 billion tons of salt, of which around 25,000 tons are extracted each year.

Geological Origins and Lithium Reserves

Sitting at an altitude of 3,656 meters above sea level, the Uyuni Salt Flat covers an astonishing 10,582 square kilometers, in the Potosí and Oruro regions of south-western Bolivia, near the crest of the Andes. It was formed as a result of transformations between several prehistoric lakes: some 40,000 years ago, the area was part of Lake Minchín, a giant prehistoric lake whose drying up left behind two more recent lakes, Poopó and Uru Uru, and two large salt deserts, the Salar de Coipasa and the much larger Salar de Uyuni.

The Uyuni Salt Flat is covered by a salt crust several meters thick, and is exceptionally flat, with an average altitude variation of about one meter across the entire surface of the lake. This crust also encloses a brine reserve exceptionally rich in lithium: it is estimated that the Salar de Uyuni holds between 50 and 70% of the world’s lithium reserves. Its huge size, clear skies and remarkably flat surface also make it the ideal place for calibrating the altitude of Earth observation satellites.

Isla del Pescado and the Colored Lagoons

The Uyuni Salt Flat hides unrivaled natural beauty and surreal landscapes. Isla del Pescado (Fish Island), so named for its shape, sits in the middle of the salt flat and is entirely covered in giant cacti, the only sign of life for miles around.

In the Eduardo Avaroa National Reserve are Laguna Verde and Laguna Colorada. Sitting at around 4,300 meters above sea level, Laguna Verde is known for its intense green color, caused by sediments containing copper minerals, and lies near the Chilean border, at the foot of the Licancabur volcano (5,930 meters). Laguna Colorada, meanwhile, takes its name from the red color of its waters, caused by the presence of minerals: every November, both lagoons host all three species of South American flamingo – the Chilean, James’s and Andean – in a truly captivating scene.

Geysers and Hot Springs

Other major stops on the Uyuni Salt Flat include Sol de Mañana, a geyser basin with boiling mud pots and sulphurous fumaroles at 4,950 meters, and the astonishing Termas de Polques, hot springs at 4,200 meters where you can take a relaxing dip in 30°C sulphurous waters.