Costa Rica’s Turquoise River – A Natural Optical Illusion
Up until four years ago, Rio Celeste, a 14-kilometer river in Costa Rica’s Alajuela province, was a complete mystery to scientists, who could not understand why its waters had an unusual turquoise color. And then they realized that it wasn’t turquoise at all. Theories regarding the turquoise color of Rio Celeste had been circulating in the scientific community […]