Azul River (Rio Grande do Sul)

The Azul River, located in the state of Rio Grande do Sul, Brazil, is a small river known for its strikingly blue waters. The unusual coloration is due to a combination of factors, including the river's source in a spring with a high concentration of dissolved minerals and its location within a forested area that provides significant shade, reducing algal growth and further enhancing the visual effect of the minerals in the water.

The river is primarily a tourist attraction, drawing visitors who come to admire its unique color. While not a major river in terms of size or navigability, its aesthetic appeal makes it a locally significant geographical feature. Information regarding the precise mineral composition responsible for the blue hue and the detailed hydrology of the river are not widely available in publicly accessible scientific literature. It is important to note that while often depicted as a pristine natural wonder, human impact and potential pollution sources should always be considered when evaluating the health and preservation of any river system.