South America
Bolivia
Uyuni
Salt desert
Salar de Uyuni
Name:Salar de Uyuni
Elevation:approx. 3,650 meters
Area:approx. 10,582 square kilometers
Length x width:140 kilometers x 110 kilometers
Thickness of the salt crust:up to 11 meters
Warmest month:July
Coldest month:December
Precipitation:approx. 150 mm / year

18 Fascinating Facts about Salar de Uyuni

 

  1. Location: The Salar de Uyuni lies in southwestern Bolivia on the Altiplano, close to the Andes and not far from the border with Chile. It is located in the Potosí Department, in a remote high-altitude landscape at around 3,650 meters above sea level.
  2. Largest salt flat in the world: Covering around 10,582 km², the Salar de Uyuni is the largest salt flat on Earth. In the dry season, it appears as an almost endless, bright white surface marked by characteristic polygonal salt patterns, while in the rainy season it transforms into a vast mirror that perfectly reflects the sky and clouds. Its exceptional flatness and the clear air often make distances appear misleading, giving the landscape a surreal atmosphere. Around 30 islands, including Incahuasi and Isla del Pescado, rise from the white expanse. They are considered the remains of ancient volcanoes.
  3. Formation of the salt flat: The Salar de Uyuni formed in a high-altitude basin in the Andes where water could not drain into the sea. Over long periods, large lakes repeatedly developed, expanding during wetter climate phases and slowly evaporating during drier periods. Each cycle left behind a thin layer of salt and other minerals, similar to how evaporating water leaves a white residue. When new water later entered the basin, it partially dissolved older salt deposits and redistributed them before further layers formed during the next drying phase. Over thousands of years, this process created the thick salt crust that now covers the Salar de Uyuni.
  4. Hexagonal salt formations: The surface of the salt flat is often covered with striking, honeycomb-like salt patterns. They form as saltwater moves beneath the hard crust and, during evaporation, continuously deposits new salt along the edges. Over time, slightly raised lines develop, forming large polygons that often resemble hexagons. While similar patterns can be found in other salt lakes, they are particularly impressive here.
  5. Ojos de Sal: The Ojos de Sal are small, usually circular holes in the salt crust of the Salar de Uyuni, where mineral-rich brine rises from below and often bubbles visibly at the surface. They form where saltwater moves beneath the seemingly solid crust and gradually dissolves it from below. Their name literally means “eyes of salt,” as the dark openings resemble small eyes in the vast white landscape.
  6. Extraction of natural resources: The Salar de Uyuni is not only a spectacular salt flat but also one of Bolivia’s most important resource regions. Alongside traditional salt extraction, potassium chloride now plays a key role, mainly used as fertilizer, while lithium is especially valuable due to its importance for batteries. Despite these vast reserves, lithium extraction remains technically complex and is still being further developed. At the same time, the economic use of the salt flat has long been controversial, as questions about territorial claims, profit distribution, and the role of local communities continue to create political and social tensions.
  7. Train cemetery: The train cemetery near Uyuni is a vast open site filled with abandoned locomotives and wagons that stand like rusting skeletons in the barren Altiplano landscape. It dates back to the late 19th century, when Uyuni became an important transport hub linking the mines of the Andes with Pacific ports through the expansion of the railway network. Raw materials such as silver and tin were transported along these routes, while goods and people also reached the remote highland region. As mining declined and extraction became too expensive to compete on the global market, many trains were simply left behind. This led to the creation of the train cemetery, which today serves as a popular photo stop and a reminder of that era.
  8. Satellite calibration: The Salar de Uyuni is highly valuable for space research because it acts as a vast natural test surface. It is extremely large and remarkably flat, with elevation differences often measuring less than 1 meter across wide areas. This allows researchers to accurately verify whether satellites are measuring distances and elevations correctly. In simple terms, the Salar functions like a natural ruler on Earth, making it possible to compare satellite data reliably and adjust it with great precision. Space agencies such as NASA and ESA use this unique environment to calibrate and test their sensors, especially laser and radar altimeters.
  9. Tunupa volcano: Tunupa is a volcano rising to around 5,321 meters at the northern edge of the Salar de Uyuni, shaping the landscape with its striking, deeply eroded slopes. Geologically, it is a very old and now inactive volcano whose form has been shaped not only by lava but also by past glaciers and water flows. In Andean mythology, it plays a central role, as legend has it that the Salar was formed from the tears and breast milk of the goddess Tunupa. Today, the mountain is a popular destination for visitors, mainly due to its impressive views over the vast salt flat and the nearby Coquesa mummy cave.
  10. Coquesa mummy cave: High on the slopes of the Tunupa volcano, above the village of Coquesa, lies a small rock cave containing pre-Columbian mummies. These human remains are around 800 years old and have been exceptionally well preserved by the extremely dry and cold climate, in some cases even retaining hair and clothing. Inside the cave, visitors can also find burial objects such as pottery and other grave goods. The mummies can be visited as part of a guided tour under controlled conditions.
  11. Life in the salt flat: At first glance, the Salar de Uyuni appears as an endless white expanse without life, and in reality the exposed salt crust is an extremely harsh environment for plants and animals. The high salt content, intense UV radiation, dry air, and extreme temperature differences between day and night allow very little visible life to survive. More diverse ecosystems can therefore be found along the edges of the Salar, in wetlands, and on islands such as Incahuasi, where salt-tolerant plants, grasslands, and giant cacti thrive.
  12. Flamingos: Flamingos are among the most iconic animals around the Salar de Uyuni and are mainly found in the region’s shallow lagoons. There, they use their specialized beaks to filter tiny organisms such as algae from the water. Three species live in the area: the Andean flamingo, James’s flamingo, and the Chilean flamingo. This makes the highland region around Uyuni one of the most important habitats for these fascinating birds in the Andes.
  13. Giant cacti: On the well-known rocky island of Incahuasi, impressive columnar cacti grow several meters tall and are often several hundred years old. Rising from the vast salt flat, they appear almost surreal and play a defining role in shaping the landscape. Despite the extreme conditions, they are also an important part of the ecosystem, providing food and shelter for animals.
  14. Salt hotels: At the Salar de Uyuni, there are indeed hotels built entirely or largely from blocks of salt, making them some of the most unusual accommodations in Bolivia. One of the best known is the Palacio de Sal near Colchani, constructed from more than 1 million salt blocks sourced directly from the Salar. Because moisture and rain can damage the material, parts of these buildings must be regularly repaired or replaced.
  15. 4×4 tours: Classic 4×4 tours are the main way to explore the Salar de Uyuni and usually last 2 to 3 days, as they extend far beyond the salt flat into remote desert landscapes, lagoons, and volcanic regions of the Altiplano. Typical stops include the train cemetery, the village of Colchani, the cactus island of Incahuasi, and colorful lagoons with flamingos in the Eduardo Avaroa Reserve. For many travelers, this multi-day journey is not just an excursion, but the true highlight of their trip to Bolivia.
  16. Perspective photos: The Salar de Uyuni is world-famous for perspective photos in which people, vehicles, or objects appear either gigantic or tiny. This effect is made possible by the nearly perfectly flat surface, the vast horizon, and the absence of clear reference points, making distances difficult to judge in images. Even slight adjustments in distance, camera height, or angle are enough to create striking optical illusions.
  17. Film location: The Salar de Uyuni is frequently used as a spectacular filming location when a landscape is needed that resembles a distant or otherworldly planet. It gained particular fame through the film Star Wars The Last Jedi, where its white expanse served as inspiration for the planet Crait, the setting of the movie’s final confrontation between the Resistance and the First Order. Its endless vastness, near-perfect flatness, and mirror effect during the rainy season make it one of the most visually impressive natural film locations in the world.
  18. Origin of the name: The name Salar de Uyuni roughly translates to “salt flat of Uyuni.” Uyuni likely derives from Aymara, an indigenous language of the Andes that is still widely spoken in Bolivia and Peru today, and can be interpreted as “enclosed place” or “area with an enclosure.”