Hierve el Agua has stunning views, and if you're coming to Oaxaca, it's a great ending ( or beginning) to a day east in the valley. We were there on a slightly colder day, so we didn't end up swimming because the water is, well, "fresco." There were people swimming, and I imagine on a hot day it would be great. The water looks a little sketchy, but you can see the spring which is a reminder that perfectly clean water is constantly circulating through. Some things to keep in mind: (1) There is some food there in case you get hungry, but I can't vouch for how good it is; (2) There is a 6 peso bathroom at the top of the hill where you can pee and change, or a free bathroom at the bottom, that I again, can't verify how clean it is or is not. (3) I think this place is better seen with a small group or private car, and I could see how you would be grumpy pants if you cam here with a large group of pasty white loud americans who only wanted cheap trinkets. (4) You will need to bring at least 30 pesos per person to pay for acess to the springs.
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