The Rio Celeste is one of Costa Rica’s most spectacular rivers. Its breathtaking light bluish turquoise color is wonderfully unique making it a favorite visiting place for tourists and locals alike. Locals will playfully explain the origin of its beautiful color like this: “When God finished painting the sky, he washed his brushes in the Rio Celeste”. How the Rio Celeste gets its unique color is a phenomenon caused by an unusual chemical reaction made possible by its proximity to a volcano and natural hot springs.
The Rio Celeste is found in the Tenorio Volcano National Park, a 32,000 acre park that is home to a large number of Costa Rica’s natural wildlife (most of Costa Rica’s feline species can be found here including jaguars, cougars, ocelots, and margays). The Rio Celeste’s blue coloring is the result of a chemical reaction between sulfur and calcium carbonate from the nearby Tenorio volcano. The sulfur and calcium carbonate is carried from the surrounding volcanic soil to the Rio Celeste by smaller streams that feed into the river. The strange brew is then heated by natural thermal steam emitted from hot thermal springs that feed into the river. After the chemical reaction, the water perfectly reflects wonderful turquoise blue waves of light.