Spanning more than 10,500 square kilometres across the high-altitude Andean plateau of southwest Bolivia, Salar de Uyuni is the world’s largest salt flat. Perched at roughly 3,650 metres (11,975 feet) above sea level, this blindingly white expanse of prehistoric salt crust and ancient minerals is one of the most surreal landscapes on the planet.
The Dual Seasons: Mirror vs. Hexagons
The character of Salar de Uyuni shifts entirely depending on the time of year:
- The Wet Season (December to April): Rain pools on the impermeable salt crust, transforming the flats into a colossal mirror that reflects the sky without a horizon line. Clouds appear beneath your feet, making it a photographer’s dream, though high water levels can restrict vehicle access to deeper sections.
- The Dry Season (May to November): The brine evaporates to expose a rugged white plain etched into natural geometric hexagons. Hard-packed ground allows 4×4 vehicles to traverse the full width of the salar, granting access to remote islands and distant volcanic routes.
Key Landmarks Across the Salt Crust
- Isla Incahuasi (Fish Island): A hilly outcrop formed from the remnants of an ancient coral reef, rising out of the sea of salt and covered in giant Trichocereus cacti—some centuries old and standing over 10 metres tall.
- The Train Cemetery (Cementerio de Trenes): Located just outside the town of Uyuni, this open-air museum features dozens of hollowed-out British-built steam locomotives abandoned in the early 20th century following the collapse of local mining booms.
- Salt Hotels: Built almost entirely from cut blocks of local rock salt—including walls, bed frames, and dining tables—properties like the Palacio de Sal showcase local architectural ingenuity.
- Ojos de Sal: Bubbling natural vents where pressurized groundwater breaks through the crust, marking active mineral processes churning beneath the surface.
Into the Eduardo Avaroa Reserve
Most multi-day expeditions pushing south toward the Chilean border cross the Eduardo Avaroa Andean Fauna National Reserve, revealing dramatic desert topography:
- Coloured Lagoons:Laguna Colorada glows crimson due to red algae and sediment, providing feeding grounds for thousands of Andean, Chilean, and James’s flamingos, while the mineral-dense Laguna Verde sits at the foot of the Licancabur volcano.
- Geothermal Fields: The Sol de Mañana geyser basin erupts with sulphur steam and boiling mud pits at nearly 4,900 metres elevation.
- Wind-Sculpted Rock Formations: The Siloli Desert houses the Árbol de Piedra (Stone Tree), an isolated volcanic rock carved into a delicate trunk by abrasive desert winds.
Practical Travel Guidance
- Acclimatisation: Altitude sickness is a major factor at nearly 4,000 metres. Spend a couple of days acclimatising in La Paz or Sucre before tackling the flats, stay hydrated, and carry coca leaves or altitude medication.
- Protection from the Elements: The high-altitude sun reflecting off pure white salt causes severe glare and burns. UV-rated sunglasses, high-factor sunscreen, and lip balm are non-negotiable.
- Temperature Swings: Daytime temperatures can be mild, but sub-zero night temperatures are standard across the Altiplano. Thermal base layers, windproof jackets, and warm sleeping gear are essential.
