Natural hot tubs have never looked this good. Set in truly ethereal surroundings amid low brush-covered mountains, Hierve El Agua (meaning ‘the water boils) is a set of bubbling mineral springs that run into natural infinity pools right on a cliff's edge with spectacular panoramas over the sierra. The act of the water dribbling over the cliff edge for millennia has created unique white mineral formations that resemble huge frozen waterfalls.
There are two ghostly ‘waterfalls’ at the site. The ‘cascada chica’ is the one nearer the visitor car park and supports four popular mineral pools (the one nearest to the lip of the cliff is manmade). From here you get perfect views of the more impressive ‘cascada grande.’ To get to the second ‘waterfall’ follow the trail for 1km to its end, where you can enjoy a much quieter more natural spot (with few bathers).
The mineral-laden water is actually cool to cold, though usually swimmable. Altogether it's an utterly unique bathing experience and stunningly beautiful to boot. There are changing rooms just above the pools.
Unofficial roadblocks – the result of a local feud – sometimes spring up close to the springs and charge you an extra M$10 to enter.