The Cascadas de Agua Azul (Spanish for "Blue-water Falls") are found in the Mexican state of Chiapas. They are located in the Municipality of Tumbalá, 69 kilometers from Palenque by the road that leads towards San Cristóbal de las Casas.
This waterfall consists of many cataracts following one after another as can be seen in the first photo in the picture gallery, taken from near the top of the sequence of cascades. The larger cataracts may be as high as 6 meters (20 feet) or so. The one pictured to the right is next to the bottom of the sequence.
The water is as blue as it looks in the pictures, and has a high mineral content. Where it falls on rocks or fallen trees it encases them in a thick shell-like coating of limestone. This can be seen clearly in one of the minor falls in one of the pictures in the gallery below, where the part of a tree that leans against the waterfall is heavily coated while the part further away is not coated. Some fully coated log shapes can also be seen inside the fall in that same picture, as well as coating on the rocks.
Wikipedia : http://en.wikipedia.org/wiki/Agua_Azul