3 Best Sights in Yucatán and Campeche States, Mexico

Perhaps the most photographed cenote in the Yucatán, this sinkhole is across the road from another one, Cenote X-Keken, about 5 km (3 miles) west of the main square. A narrow stairway leads to crystal clear water where tree vines dangle overhead and hundreds of birds nest between the stalactites. Don't be alarmed by the tiny Garra rufa fish that nibble at your feet—they are actually eating away the dead skin cells. Guides offer tours for tips.

Five kilometers (3 miles) west of the main square, you can swim with the catfish in a lovely, mysterious cave illuminated by a small natural skylight. There are toilets and changing facilities but no lockers. Directly across the street is the equally stunning Cenote Samulá. Guides offer tours for tips.

A large, round, and beautiful sinkhole right in town, Cenote Zací—zací means "white hawk" in the Mayan language—is sometimes crowded with tourists and local boys clowning it up; at other times, it's deserted. Leaves from the tall old trees surrounding the sinkhole float on the surface, but the water itself is quite clean. If you're not up for a dip, visit the adjacent handicraft shop or have a bite at the popular, thatched-roof restaurant overlooking the water.  We recommend paying the extra MX$30 to rent a life vest here.