From a protected cove on Long Island, Dean’s Blue Hole—Earth’s deepest known underwater cave—plunges more than ... of the inland blue holes—deep, dark, sheltered, with little tidal ...

but the underwater sections are simply breathtaking. Located on New Zealand's North Island, these caves are famous for their glowworms that light up the dark tunnels like stars in the night sky.

The underwater caves of the Yucatán Peninsula ... these animals had to venture down dark, dry cave passages to reach drinking water, sometimes surprisingly far away from an entrance.

Take a deep breath and dive below the surface with cave-diving experts and scientists in the video above. Find out what it takes to plunge into the dark and mysterious world of underwater caves. Caves ...

Krubera Cave in the republic of Georgia is currently the deepest known cave, at 7,208 feet. But Dark Star, with so many areas still to survey, is a prime candidate to take over the title.

But hearing about what was going on underwater rather than seeing it for herself ... “It’s a very surreal experience,” Beddows says of her visits to the eerily dark, nearly football field–size cave.

There are caves all over the planet, but only a few have been explored. These dark spaces are sheltered from the weather and provide a steady temperature, making them ideal homes for an enormous ...

The cave's underwater passages are winding and maze ... When Zhou was rescued at around 8:30 pm on February 8, he had spent days in a dark, confined space without food and was extremely weak.