being there

by beth kohn

Sunken swimhole

IN THE STICKY jungle heat, the last thing we wanted to do was stuff ourselves into rubber wetsuits. We were already soaked with sweat, and rubber isn't well-known for its breathability. On the brighter side, our vicious entourage of mosquitoes would have less surface area to dive-bomb. As the guide ushered us toward a metal ladder leading into the ground like a manhole to Hades, we ditched our tubes of sunscreen and fled our buzzing hell on earth.

Sprinkled throughout Mexico's Yucatán Peninsula, between the ruins of Mayan cities and the Wilma-weary Cancún coast, are freshwater limestone sinkholes called cenotes that offer a perfect hybrid of two of my favorite outdoor pastimes: swimming and spelunking. Created by the slow leaching of surface water and the eventual collapse of cavern roofs, the resulting rock formations create trippy fantasy worlds of eerie underground caverns, dramatic aboveground craters, and submerged, winding rivers. Some seemingly bottomless cenote pools plummet as deep as 300 feet into the earth.

In the subterranean landscape of Hilario's Well, an underground river, bleached stalactites stab from the cavern roof like deadly rows of sharpened goblin teeth. At a developed cenote at the Hidden Worlds swim-and-dive complex, near the palapa-lined beaches of Tulum, south of Cancún, rounded mounds the shape of baseball bats sprout from the floor, and filtered spotlights accentuate jagged rock stacks. Like the melted drippings of massive candles, chunky orange stalagmites ooze up from below. Columns of thirsty ceiba tree roots stretch dozens of feet down from the vaulted cathedral ceiling, diffusing into furry psychedelic tentacles below the waterline. We felt as if we'd dropped into the jaws of one of H.R. Giger's demonic Alien creations and weren't surprised to hear that Hidden Worlds had been the backdrop for a recent sci-fi horror flick.

Cenotes were the primary source of water for the Mayan city-states that once dominated the Yucatán, a region with no surface lakes or streams. In the early 1900s, an enterprising US consul named Edward Thompson eyed the unexcavated and then-unprotected ruins of Chichén Itzá, bought it for a song, and began dredging the 100-foot depths of a pool now called the Cenote Sagrado, or "sacred cenote." He and subsequent archeologists discovered troves of ornate artifacts including offerings of gold, pottery, and jade jewelry, supporting the theory that the Maya considered this enormous well to be holy. Adding to the cenote's mystique was the discovery of many human remains. It's unclear whether these ancient skeletons were ritual sacrifices or just unfortunate looky-loos who couldn't tread water.

Snorkel masks suctioned onto our faces and diving flashlights in hand, my friend Lulú and I cruised the nooks and crannies of the warm, placid pool. Underwater illumination bathed swaths of clear blue water, and the beams of our torches sliced through the shadows like light sabers. We hovered over schools of impish silver fish darting between limestone shelves. As I carefully came up for air in a compact space between water and prickly ceiling spikes, something shot past me with a shriek. Adjusting my eyes, I could make out an intermittent trickle of bats flitting between the gothic chandeliers near my head.

I'm not spooked by the bats. It's the lazy beaches quilted with oversize towels and umbrellas that make me want to scream underwater. The Yucatán's countless cenotes offer a more adventurous approach to swimming. And finding these perfect blue swimming holes is easy enough. The tricky part? Making yourself come up for air.

Beth Kohn is a freelance writer and opportunistic swimmer shackled to dry land in San Francisco. Taunt her at fiercesf@igc.org. Next week: Kohn reports back from the ruins of Campeche.

Trip planner

Reading An excellent general guidebook, Moon Handbooks Yucatán Peninsula lists more than a dozen cenote sites. Steve Gerrard's beautifully illustrated coffee table book The Cenotes of the Riviera Maya (www.cenotesoftherivieramaya.com) gives detailed information on more than 50 cenotes on the eastern Yucatán coast. John L. Stephens's 1841 classic two-volume Incidents of Travel in Central America, Chiapas, and Yucatan is the first guidebook on the treasures of the Maya.

Getting wet Tulum area: Hidden Worlds (984-877-8535, www.hiddenworlds.com.mx) has snorkel tours from $25 and one-tank dives starting at $50. The Cenote Dive Center (984-871-2232, www.cenotedive.com) takes groups to multiple cenote sites. There are also a number of signed cenotes on the road between Tulum and Cobá.

Between Mérida and Cancún: After a scorching day at Chichén Itzá, Cenote Ik Kil (985-851-0039, www.wohlmut.com/Maya/Ik-Kil.htm), just two miles from the ruins, is a popular spot to cool off in a collapsed roof cavern ringed by waterfalls and lush greenery. The town of Cuzamá has a series of cenotes accessed by a horse-drawn trolley on an old henequen hacienda.

Between Mérida and Campeche: A number of cenotes can be found near the town of Chochola, including the developed Cenote Chen-Ha.