Laguna Colorada,
Bolivia.

Laguna Colorada is a 60 km² blood-red salt lake at 4,278m in the Eduardo Avaroa National Fauna Reserve, southwest Bolivia. Its red colour comes from Dunaliella salina algae and cyanobacteria. The lake averages 20–35cm depth and is the world's most important breeding site for the Andean flamingo (Phoenicoparrus andinus) — approximately 65% of the global population breeds here. Visited on Day 2 of the standard 3-day 4×4 tour from Uyuni.

The red colour has two main causes: (1) Dunaliella salina microalgae produce beta-carotene (the same pigment that makes carrots orange) as protection against intense UV radiation at 4,278m altitude; (2) cyanobacteria thrive in the hypersaline water and add pigment. Colours range from pale pink to blood red depending on algae concentration, wind and season. The white islands in the lake are borax (sodium tetraborate) precipitations from ancient geothermal activity.

October–January is best for flamingo numbers — the Andean flamingo breeding season can concentrate up to 25,000 individuals of three species. The dry season (May–October) offers reliable 4×4 access and clear skies. June–July has the coldest nights (-20°C) but the clearest skies. The rainy season (November–March) can make access tracks difficult but the landscape is more dramatic. Flamingos are present year-round.

Only by 4×4 via unpaved altiplano tracks — no public transport. The standard option is the 3-day tour from Uyuni ($150–280 USD/person in 2026): salt flat Day 1, Laguna Colorada and Sol de Mañana Day 2, Laguna Verde Day 3. Distance: ~160km south of Uyuni (5–6 hours). Alternatively from Chile: San Pedro de Atacama → Uyuni reverse circuit (3 days). Dozens of agencies in Uyuni offer this tour — book 1–3 days ahead (3–5 days in July–August).

Laguna Colorada is at 4,278m — 622m higher than Uyuni (3,656m). Yes, altitude sickness (soroche) can affect even acclimatised travellers at this elevation. Acclimatise in Uyuni for at least 2 nights before attempting the southwest circuit. Common symptoms: headache, fatigue, shortness of breath. Diamox (acetazolamide) can be prescribed preventively. Descend immediately if severe symptoms appear (confusion, inability to walk, chest pain).

Daytime (11am–4pm): 5–15°C in dry season with constant cold wind. Dawn when most tours arrive (4–7am): typically -8 to -12°C. Nights: -10 to -20°C year-round, coldest June–July. Essential clothing: down parka, 3–4 layers, waterproof ski gloves, wool hat, thermal base layers, insulated boots. The combination of altitude, wind and cold makes this far more extreme than Uyuni.

Yes — it is consistently rated one of the most extraordinary natural spectacles in South America. The blood-red water, three flamingo species, white borax islands, active volcanoes on the horizon and extreme altitude silence create an experience unlike anything else on the continent. The 3-day tour from Uyuni is one of Bolivia's benchmark travel experiences. Main caveats: basic accommodation in cold temperatures and the physical challenge of 4,278m altitude.