Hierve el Agua (The Water boils) is a petrified cascade system, formed by calcium carbonate. The cascades are of natural origin and they formed thousands years ago, by the water draining with high mineral content. The place is located to about 80 km of the city of Oaxaca de Juárez, in the state of Oaxaca, in Mexico, in the neighborhoods of the archaeological ruins of Mitla.
It is also a place of archaeological interest, just because it has a complex system of irrigation and terraces built by the zapotecas about 2.500 years ago. The water has a temperature of about 25 degrees Celsius and the cascades have about 50 meters high.