Salar de Uyuni

The biggest mirror in the world

Uyuni is a dazzling white salt flat of 10,000 km² at 3,600 m altitude. In the rain a thin layer of water covers it and it turns into a giant mirror — sky and ground merge, and people seem to walk on clouds! The salt is 10 metres thick, and beneath it lies the world's biggest supply of lithium — for phone batteries. Satellites check their instruments on this flat surface.

Salar de Uyuni is the world's largest salt flat, 10,582 km² on Bolivia's Altiplano at 3,656 m; the remnant of Lakes Minchin and Tauca, which dried up 40,000 years ago. The salt crust is 1–10 m thick; beneath it lies lithium-rich brine — 50–70% of the world's reserves (21 million tonnes). Its surface varies by just 1 m over 100 km — the flattest place on Earth; NASA and ESA calibrate satellite altimeters here. In the rainy season (December–April) 5–10 cm of water creates the 'mirror effect'. Incahuasi Island, covered in cacti, is an ancient volcano. There are hotels built of salt. Every November three species of pink flamingo breed here. 1 million tourists a year — the backbone of Bolivian tourism.

Fun facts

• Uyuni varies by just 1 m over 100 km — the flattest place on Earth.
• Under Uyuni lies half the world's lithium — 21 million tonnes.
• Uyuni has hotels built of salt — walls, tables and beds made of salt!