This River in Colombia Is a Liquid Rainbow You Have to See to Believe

What’s at the end of a rainbow? Perhaps it’s not actually a pot of gold, but a fantastic and colorful river.

Caño Cristales in Colombia's Serranìa de la Macarena National Park is dubbed the “river of five colors," “liquid rainbow," or "melted rainbow" because of the many hues you can see beneath its clear waters. In certain light and water conditions, bright greens, yellows, reds, and purples may appear to flow down the river. Sometimes, the river can also appear a bright blue, hot pink, orange, or a deep maroon.

Although it looks like magic, the vibrant coloration can be attributed to a weed called Macarenia clavigera, a kind of aquatic plant that’s different from algae or moss. The right water level and weather conditions make all the difference as to which colors you can see in the water.

Macarenia clavigera clings to the billion-year-old quartzite rocks on the riverbed. It occurs in a few different rivers throughout Serranìa de la Macarena (hence its name), but Caño Cristales gives it just the right conditions to reach optimum brightness. The best time to go is in full sun, when the light reflects the colors. The waters must be high enough for the plants to thrive (as opposed to drying out and turning brown), but not so high that you can’t see the river bottom. Generally, the colors are at their peak vibrancy between July and November.

To get to the river, travelers must first fly into Villavicencio, in central Colombia, then charter another plane to La Macarena. There, travelers can hire a guide to take them to Serrania de la Macarena, the fairly isolated mountain range that provides access to the river.

Tours are offered through Viator, Uncover Colombia, Amazon Adventures, and more. Some of the tours provide the opportunity to swim in the rainbow-colored waters — a real bucket list-worthy activity — but if you partake, do so responsibly. Make sure not to wear sunscreen, bug spray, or any other product that could damage the color-emitting plants or the local wildlife that rely on the river.