Hierve el Agua, Natural mineral springs and rock formation in San Lorenzo Albarradas, Mexico.

Hierve el Agua is a rock formation fed by natural mineral springs in San Lorenzo Albarradas, Mexico. The white stone walls rise from the mountainside and appear as frozen waterfalls, descending across several levels.

A civilization built an irrigation system on the slope over two and a half millennia ago to supply fields in the surrounding valleys. The ancient channels and basins testify to this early management of water and mineral deposits.

The name "Hierve el Agua" comes from two of the four springs on the Amphitheatre ledge, which bubble up from the level floor as if the water were boiling. The site lies in Mixe territory; the nearest communities are San Lorenzo Albarradas and San Isidro Roaguía. Zapotec irrigation canals cut into the mountainside more than 2,500 years ago survive only as vestiges, and the archaeological area has not been fully explored.

The pools at the upper edge invite bathing while overlooking the mountains and valleys of Oaxaca. Access follows a path along the cliff that requires sturdy footwear.

Two of the four springs on the Amphitheatre side rise from level ground and appear to bubble up; this bubbling, probably caused by underground currents, gave the site its name, "the water boils." The springs keep depositing calcium carbonate, a process visible on the walls of the artificial pools.