Ten thousand square kilometres of salt flat, flat to within a metre across its whole width, which in the wet season becomes the largest mirror on earth.
What it is
The world’s largest salt flat: about 10,600 square kilometres of it at 3,656 metres, the dried bed of a prehistoric lake. It is so flat — a variation of less than a metre across a hundred kilometres — that satellites are calibrated against it.
Underneath is somewhere between a quarter and a half of the world’s known lithium reserves, which is a live political and environmental question in Bolivia and worth knowing about before you arrive.
Wet season or dry season
This is the only decision that matters.
December to April, the wet season. A few centimetres of water sit on the surface and turn the whole flat into a perfect mirror reflecting the sky. It is the photograph everyone has seen. The trade-offs: parts of the flat become inaccessible, Incahuasi island may be unreachable, and the three-day tour route to Chile is sometimes cut.
May to November, the dry season. The surface dries into a honeycomb of salt polygons stretching to the horizon, the whole flat is drivable, and the three-day tour across the southern altiplano to the Chilean border runs reliably. No mirror.
The perspective photographs — a person standing on a wine bottle, a dinosaur eating someone — need the dry season and a good driver who knows how to compose them.
The three-day tour
The classic trip, run in 4x4s with a driver and a cook, usually Uyuni to San Pedro de Atacama or the reverse.
Day one: the train cemetery, the salt flat itself, Incahuasi island with its enormous cacti, a night in a salt hotel.
Day two: the southern lagoons — Laguna Cañapa, Hedionda, Colorada, which is a deep red from algae and full of flamingos — across high desert at 4,000m and above.
Day three: the Sol de Mañana geysers before dawn at 4,850m, hot springs, and the Laguna Verde under Licancabur volcano before the border.
It is cold, high and basic. Accommodation is dormitory-style with no heating on at least one night, and the second night is often above 4,000m.
Choosing an operator
This matters more here than almost anywhere in this guide. There have been fatal accidents involving speeding, drink-driving and vehicles in poor condition. The cheapest quotes in Uyuni are cheap for reasons.
Ask directly: how old is the vehicle, does the driver do this route regularly, is there a spare driver on the three-day tour, and is there oxygen in the car. Pay more than the bottom price. Read recent reviews rather than old ones.
Altitude
Uyuni is at 3,656m and the tour goes higher. Arriving from La Paz you are already acclimatised; arriving from sea level you are not, and the third day at 4,850m before breakfast is not the place to find that out. See the Andes page.
Practical
Sunglasses and very high factor sun cream are not optional — the reflected UV off white salt at 3,600m burns the underside of your nose and chin.
Warm layers, including for sleeping. Nights on the tour fall well below freezing.
Cash in bolivianos; card acceptance in Uyuni is limited.
Waterproof footwear in the wet season, or you will spend the day in wet socks.
