The Salar de Uyuni is the world's largest salt flat, a blinding white expanse of over 10,000 square kilometres in southwest Bolivia, at 3,650 metres on the Altiplano near the crest of the Andes.
The word that comes up most is surreal. A dried hill covered in giant cacti — once a coral island in a prehistoric lake — rises from the flattest surface on earth. Beyond the salt, extinct volcanoes wear bands of colour from successive eruptions. Lakes turn red from bacteria, white from minerals, green from arsenic, all ringed by pink flamingos bracing against the wind at 4,000 metres. The landscapes south of the Salar look like something Salvador Dali dreamed up, and viscachas — rabbit-like creatures with long curling tails — dart through miniature canyons.
You can visit, and it is remarkably cheap. Practically speaking, you go with a tour: one day on the salt flat itself, then two to three more days through the mountains to the south. Prices in Uyuni start around US$60 per person, everything included. Around 60 agencies in town compete with essentially the same product — the tourist information office can help you choose. If you form your own group you can customise the route. For a small surcharge, the jeep can drop you at the Chilean border, from where a bus runs to San Pedro de Atacama.
If you are coming from Argentina, consider taking the trip from Tupiza instead. It costs a bit more, but you spend a day and a half without seeing another tourist and skip the least interesting stretch of the Uyuni route. There is no need to book from La Paz — you will likely be approached by agencies the moment you step off the bus in Uyuni, at whatever hour of the night.
The trip is better in summer (November to March), when temperatures are less brutal, though this is also the wet season and the Salar may be flooded. A thin layer of water turns the salt flat into a giant mirror reflecting the sky — an even more surreal experience, though some visitors insist on seeing the dry white expanse. Accommodation on the tour is basic regardless of which agency you choose, and hot showers are rare.
The Salar formed around 40,000 years ago when the giant prehistoric Lago Minchin dried up, leaving behind two modern lakes and two vast salt deserts. Uyuni is the larger, roughly 300 times the size of the Bonneville Salt Flats in the United States. It contains an estimated 10 billion tonnes of salt, of which less than 25,000 tonnes is extracted each year. Every November, the Salar becomes a breeding ground for three species of South American flamingo: Chilean, James's, and Andean.