Caño Cristales, the River of Five Colours
For a few months each year, a river in Colombia turns red, yellow, green, blue and black.
What was reported
Caño Cristales is a river in the Serranía de la Macarena, in central Colombia. For most of the year it looks like any clear mountain stream. But between roughly July and November, its bed bursts into colour: bright red and pink, with patches of yellow, green, blue and black.
It is often called the most beautiful river in the world, or the liquid rainbow, and it was long hard to reach because of the region's conflicts.
Explanations offered
The red colour comes from a water plant, Macarenia clavigera, that grows on the rocks of the riverbed and turns red when the water level and sunlight are just right. Green algae, yellow sand and dark rock add the other colours.
- When
- Every year, from about July to November
- Where
- Serranía de la Macarena, Meta, Colombia
- Witnesses
- Visitors and scientists
- Status
- Explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.