Nestled within the Sierra de la Macarena National Park in Colombia's Meta Province, Caño Cristales is one of South America's most spectacular landscapes. Often called the "river of five colors," it's so vibrant at certain times of the year that the riverbed appears almost as if it were painted with watercolors.
Photo: flashpackerconnect
This wonder isn't due to some mysterious mineral or lighting effects. The true "artists" of Caño Cristales are a unique aquatic plant called Macarenia clavigera. They cling to rocks at the bottom of the river and change color depending on light conditions, water level, and environment. When thriving, these plant mats create striking red, pink, or purple streaks against the clear water.
The river's other colors come from a combination of vegetation, algae, rocks, sand, and the reflection of the water. Therefore, depending on the section of the river and the time of observation, one may encounter red, pink, yellow, green, blue, and black. This combination is why the name "five colors" is merely a symbolic description; Caño Cristales may actually exhibit many more shades.
Photo: ndtv
Interestingly, the river isn't always brilliantly colored. This unique phenomenon depends on water levels and sunlight, and is usually most prominent during the rainy season, from around May to November, when conditions are ideal for Macarenia clavigera to thrive. In 2026, the Caño Cristales tourist season officially opened in late May with regulations aimed at protecting this unique ecosystem.
Caño Cristales is also special because of its geographical location in the Sierra de la Macarena. It's a crossroads between Colombia's major ecosystems, resulting in incredible biodiversity. Visitors can encounter birds, monkeys, turtles, reptiles, and many other animals on their journey along the river.
Photo: tabi-choku
But it is precisely this fragile beauty that makes Caño Cristales in need of strict protection. Visitors must follow designated routes and adhere to environmental regulations; substances like sunscreen or insect repellent can negatively impact the aquatic ecosystem.
Caño Cristales, therefore, is not really a "rainbow river." It is a living ecosystem that has transformed the riverbed itself into a giant palette of colors, and that palette only appears when nature allows it.
Source: https://khoahocdoisong.vn/bi-mat-dong-song-ngu-sac-dep-nhu-tranh-ve-o-nam-my-post2149120607.html
