Cenotes, Yucatán Peninsula
Concierge.com's insider take:
The Yucatán Peninsula is one of the flattest places on Earth—just a limestone shelf with clusters of low, scrubby jungle and a lot of imported greenery. As a result, the region's endless inches of rain collect in a series of sinkholes called cenotes, which feed vast subterranean lakes and rivers. The cenotes make for unusual adventure opportunities (swimming, snorkeling, and cave-diving). Hidden Worlds operates dive and snorkeling trips through deep, dark waters into underground caves filled with eerie formations, along with a zip-line roller coaster, cenote-rappelling, and a SkyCycle (Carretera 307, Km 243; 52-984-877-8535).
Signs for other caves and cenotes pop up all along Highway 307. Most are on ejido land (owned by a local collective) and provide some income for residents. For less than $8 you can enter El Jardín del Edén, between Playa and Tulum, and leap like Tarzan into a huge cenote—or climb down a few slippery steps to dive into cool green water, swim to one of several flat rocks, and snooze in the shade of gnarled trees. Don't be alarmed when all you see by the road is a small stick shack—the attendant inside will gladly collect your money and direct you to a large parking lot with bathrooms, showers, and changing rooms. At Manatí in Tankhah, just north of Tulum, a large, open lagoon is part of a long underwater cave system that ends at the sea. Shy manatees were once present here, but have headed to more secluded areas. Gran Cenote, west of Tulum on the road to Cobá, is a favorite spot for serious divers exploring bottomless, endless caverns with amazing rock formations.—Maribeth Mellin