One place, two very different landscapes
The Uyuni Salt Flat is the largest salt desert in the world, covering more than 10,000 km² of white crust on the Bolivian altiplano. Between May and November, the dry season, the surface is firm and cracked into a hexagonal pattern that can be driven across freely by 4x4, ideal for the perspective-trick photos that made the place famous. Between December and April, the rainy season, a thin layer of water covers the flat and turns it into a perfect mirror that doubles the sky: it's the most sought-after image on social media, but also the least predictable, since it depends on each week's rainfall.
What a typical tour includes
Most trips leave from the town of Uyuni on one- to four-day tours. The one-day version usually covers the train cemetery, a salt-producing village, Incahuasi Island with its centuries-old cacti, and sunset over the salt flat. Multi-day tours continue into the Bolivian southwest, with the coloured lagoons, the Sol de Mañana geysers and the Polques hot springs, ending near the Chilean border or back in Uyuni.
Before you travel
Altitude — the flat sits above 3,650 metres — and the night-time cold, which can drop below freezing even in summer, are the two factors to plan around: layered clothing, strong sun protection against the salt's glare, and a day of acclimatisation in La Paz or Uyuni beforehand if you're coming from sea level. Since the landscape depends on that week's weather, it's worth booking just a few days ahead once you're in Bolivia rather than fixing the date months in advance.