HIERVE EL AGUA, Spanish for “the water boils,” is a geological phenomenon in the heart of the Oaxaca state of Mexico. What looks like a waterfall is actually hardened mineral deposits left by water which bubbled out from the rocks, slowly dripped down and calcified over thousands of years. It is one of only two petrified waterfalls in the world, the other is in Turkey.

There are two mineral pools at the edge of the cliff containing calcium carbonate, magnesium and just a touch of sulfur. They’re not hot, they don’t boil, and they’re perfect for swimming on a hot day.

The bubbling springs used to supply water to canals and terraces which led into the valley. It was one of the most intricate and complete terraced systems in Mesoamerica, but it shut down somewhere around the 1300’s—and the canals are all but gone.

Hierve El Agua has two ‘waterfalls’, the big one, Cascada Grande, and a smaller one, Cascada Chica.

How to get there

Hierve el Agua is about an hour and a half southwest of Oaxaca city — if you’re driving directly. There are other options on how to get there.

One: Hire a driver from Oaxaca. This will probably cost you around $70-100—depending on who you hire.
Two: Take a Colectivo (shared taxi) or Bus to Mitla—where there are some awesome ruins—and then transfer to a shared truck or van which will take you to Hierve el Agua. This is the rough rider way to go (and also the cheapest).
Three: Book a tour from Oaxaca—they last anywhere between 5-9 hours—and usually include time in Mitla.

What to consider

  • Arrive early, the site gets crowded during high season.
  • There are changing rooms close to the parking lot if you want to take a dip in the mineral pools.
  • Entrance to the springs is 25 pesos per person (~$1.50)
  • It’s a fascinating day-trip from Oaxaca.
  • Mitla is worth a look and see—it’s the second most important archeological site in the state of Oaxaca.