Caño Cristales (English: Crystal Spout) is a Colombian river located in the Serrania de la Macarena province of Meta. It's a tributary of the Guayabero River. The river is commonly called the "River of Five Colors" or the "Liquid Rainbow", and is even referred to as the most beautiful river in the world due to its striking colors. The bed of river in the end of July through November is variously colored yellow, green, blue, black, and especially red, the last caused by the Macarenia clavigera (Podostemaceae) on the bottom of the river
The Serranía de la Macarena is located on the border of three large ecosystems, each of them with high diversity of flora and fauna: the Andes, the Eastern Llanos, and the Amazon rainforest. Plant and animal life are struggling with the lack of nutrients on the solid rock surface of the tableland and have developed diverse adaptations. The representative biome of the Serranía de La Macarena is the hydrophytic rainforest: hot, warm, and cold. The tableland is home to about 420 species of birds, 10 species of amphibians, 43 species of reptiles, and 8 primates.