Amazing underwater caves where you can swim and scuba dive
DOS OJOS (TWO EYES)
This cavernous cenote with double entry points—hence the moniker "Two Eyes"—is so incredible it was featured in the IMAX flick Journey Into Amazing Caves and an episode of Discovery Channel's Planet Earth. It's perfect for snorkellers, and though you have to be experienced to scuba dive there to begin with, you'll also need to be seriously brave to surface in the system’s bat cave—which, not surprisingly, earns its name by being inhabited by bats.
While the giant Cocklebiddy Cave tends to steal the limelight in Australian cave diving circles, it’s only suitable for very experienced practitioners of the art. On the other hand, Cave Diving Down Under says that at the equally awe-inspiring Piccaninnie Ponds, snorkellers with a permit can swim above the chasm, a canyon-like area, and see into the depths below.
Florida has a wealth of freshwater underwater caves to explore, but Ginnie Springs stands apart for its accessibility and crystal-clear water. There’s no need for extra training to explore the large cavern in Ginnie Springs; it’s been deemed safe enough for open-water certified scuba divers to enter. The upper portion is lit by sunshine filtering through the entrance—an impressive sight. There’s also the Devil’s Ear cave system for qualified technical divers, with more than 30,000 feet of underground passages.
THE GROTTO AT BRUCE PENINSULA NATIONAL PARK
In Ontario’s Georgian Bay, waves have carved out the setting for this luminescent body of water, lit from an underwater passage. This part of the Niagara Escarpment is full of caves, but this spot is the largest and draws crowds to its rich turquoise water. The water’s a great way to cool down after the 30-minute summer hike to the coast.
Also in the Yucatan Peninsula, this semi-sunken cave with an underground river gives folks a chance at subterranean swimming without the troublesome training. First discovered in 2005—when a Mayam farmer stumbled across an entrance while chasing an iguana—it opened in 2008 to the public for tours to show off its stalactites, stalagmites, gours, helictites and other marvelous speleothems.
Taking its name from the dramatic stalactites and stalagmites, this five-chamber cave, four of which have air pockets for surfacing, was once open-air, until sea levels rose after the ice age. While some list this as an intermediate dive, unless you’re trained in cave diving this is one to admire from afar.
Leave the wet suit at home—this spa in Tuscany is built around a grotto’s thermal waters, with the underground lake’s temperature a balmy 93 degrees Fahrenheit. The Grotta Giusti Spa offers training and guided scuba excursions in the cave for people with open-water certification. There’s plenty of formations to see, but like the spa itself, it’s a very intimate, meditative experience.
Baileys Bay, Bermuda
PROSPERO’S AND CATHEDRAL CAVE
Bermuda's Grotto Bay resort maintains two caves: Prospero’s (pictured), which houses a public spa below the stalactites; and Cathedral, which has a dock for resort guests to enter the warm ocean water for a swim.
In the hot springs area of Midway, Utah, this 10,000-year-old, 55-foot-high travertine dome houses a geothermal pool. You may recognize it from the film 127 Hours, when James Franco drops into water. Thankfully, a tunnel blasted into the rock means you may walk to dock. Book ahead to scuba dive to depths of 35 feet or snorkel in the 90 degree waters.
Shafts of brilliant light pierce the gloom in this 100-foot long Maui County cavern. The sight is caused by the sun shining through openings in the lava dome’s ceiling, creating a stained-glass effect, hence the name. Unlike some sites, the First Cathedral is teeming with marine life, and there’s a Second Cathedral, another enormous lava tube with dramatic arches, to dive as well.