River of Five Colors

Caño Cristales has been referred to as the "river of five colors", "the river that ran away to paradise," and "the most beautiful river in the world." It is indeed a unique biological wonder. For most of the year, the Caño Cristales is indistinguishable from any other river, with a bed of rocks covered in dull green mosses and a cool dark blue current. However for a short period each year the river blossoms in a rainbow of colors.
During a brief span between the Colombia´s wet and dry seasons, when the water level is just right, the many varieties of algae and moss bloom in a dazzling display of colors. Blotches of amarillo, blue, green, black, and red--and a thousand shades in between--coat the river.

A number of the more adventurous Colombian tourist agencies will fly travelers to the nearby town of La Macarena. The river, which is roughly 20 meters wide and runs for 100 kilometers, is rather remote. Without any roads leading to the river, the Caño Cristales must be accessed by horse. Via