The Caroní River is a major river of the Orinoco basin in South America, having its source in South Eastern Venezuela, in the Guiana Highlands. It's waters have a black color (i know from swimming it). Some people believe this color is due to the amount of Iron around the riverbend, but actualy the color of the water is due to the amount of decomposed plant sediments the water pushes across with its flow. The Caroní river meets with the Orinoco river and merges into it for aproximately 13km. The two rivers meet where the city of Guayana (San Felix and Puerto Ordaz) now exists.

The river has been dammed for the production of energy.The power of the water has been used by man to produce hidroelectric energy. Today it has 5 different damms. They are: La presa "Raúl Leoni" in Gurí, Macagua I, Macagua II and Caruachi.

The city of Guayana, and the Alcaldia Mayor de Caroní (ALMACARONÍ) has for the past 15 years conducted a swim race of the rivers Orinoco and Caroní where around 900 competitors meet. The "Paso a Nado Internacional de los Rios Orinoco-Caroní" is celebrated every year close to the 19th of April on a sunday. This competition has gained importance worldwide and is one of the swim-meet with the most competitors worldwide.