(REFLEXIONES) Caño Cristales es a river in Colombia, South America, described as “the most beatiful stream in the world”; also called” the most beautiful river that escaped from paradise" Caño Cristales is located in the Sierra de la Macarena National Park, within the Municipality of the same name in the Meta Department of Colombia. The river is relatively short, with a total length of about 100 kilometers, and about 20 meters wide. In the local language is known as a “caño”, which is a water body of size between a river and a creek. Caño Cristales is also known as the river of 5 colors. The pigmentation in the pictures is due to algae and moss that cover the rocks that form most of its bottom. The algae and moss grow in yellow, blue, green, black and red, creating the incredible contrasts that make the river an amazing color spectacle, and an unforgetable experience to the visitors to this zone in Colombia. The red color is due to an algae named Macarenia clavigera. The intensity of the colors of the algae and moss in the bottom varies with the flow of the river, which appears to be optimal during the rainy season from June to November. Throughout the stream, depressions in the rocks at its bottom form magnificents pools, named “marmitas de gigante”. These depressions or pools were carved in the rocks by erosion resulting from harder pebbles and boulders carried by the stream. At certain points in the river, whirpools are formed by the flow, where the pebbles and boulders flow in circles slowly eroding the bottom of sections of the channel, and through the millenia causing the depressions shown.). Caño Cristales was named as a World Biological Heritage Resource. The best time to visit the zone is from June to November, when the colors are more intense due to the abundant rainfall and runoff.