A unique biological wonder, Caño Cristales has been referred as the "river of five colors," "the river that ran away from paradise," and "the most beautiful river in the world."

For most of the year, Caño Cristales is indistinguishable from any other river: a bed of rocks covered in dull green mosses are visible below a cool, clear current. However, for a brief period of time every year, the river blossoms in a vibrant explosion of colors.

During the short span between the wet and dry seasons, when the water level is just right, a unique species of plant that lines the river floor called Macarenia clavigera turns a brilliant red. It is offset by splotches of yellow and green sand, blue water, and a thousand shades in between.