Cano Cristales, however, is 100 percent natural. A booming population of the riverweed Podostemaceae thrives on the 60-mile river's floor, its vibrant red hue plainly visible through the babbling brook. Elsewhere, a brilliant combination of rocks, algae and sand is responsible for the remaining colors.
The landmark reveals its true majesty for only a few weeks in the autumn. During the rainy season, the river runs too deep and and too quickly for visitors to see through its water. During the dry season, water is not abundant enough to support the plant life responsible for the colorful show.
According to Atlas Obscura, the river is not easy accessible; visitors must fly into a nearby town and make the journey through Serrania de la Macarena National Park on horseback.