Although Hierve El Agua translates as boiling water, the springs  that seep from the side of the limestone mountain less than an hour’s drive east of Mitla  aren’t hot. Instead, they are loaded with minerals.
These minerals over time have built up into rock-hard deposits, forming great algae-painted slabs in level spots and, on steep slopes, accumulating into what appear to be grand frozen waterfalls.
Note: A local community dispute has unfortunately led to the closure of Hierve El Agua cabañas  and sometimes even the whole park. Before planning a visit, check with the state tourist information office in Oaxaca City  (Murguia 206, tel. 951/516-0123, 951/502-1200, info [at] aoaxaca [dot] com, www.oaxaca.travel ).
Get there by riding an Ayutla-bound Fletes y Pasajes bus east out of either Oaxaca City  (camionera central segunda clase) or Mitla  on Highway 179 just east of town. Get off at the Hierve El Agua side road, about 11 miles (18 km) past Mitla. Continue the additional five miles (eight km) by the local bus marked San Lorenzo–Hierve El Agua.
Drivers, head east from Mitla  along Highway 179. After approximately 11 miles (18 km), follow the signed gravel side road that forks right another five miles (8 km), through San Lorenzo village to Hierve El Agua. (Warning: Until they get around to paving it, the clay roadbed through San Lorenzo village and beyond is extremely slippery when wet with rain. Under such conditions, unless you’re driving a good-traction four-wheel-drive vehicle, park your car in the village and walk the final quarter mile (0.4 km), which steeply descends to the Hierve El Agua entrance.)