Take a dip beneath the stalactites in this amazing cenote.

There's a mini version of Iguazu Falls hidden in the Balkans, and it's got a rope swing.

A perfectly circular lake is formed by the crater of an ancient underwater volcano.

A magical sinkhole on the Yucatán Peninsula is adorned with mini waterfalls and hanging vines.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

Unparalleled stargazing, one of Colombia's best observatories, and a swimming pool can all be found in the middle of this ancient tropical forest.

The gathering point of an old Melbourne swimming club was site of a historic, world-record dive in 1918.

A sinkhole and now a swimming hole, too, full of dazzling turquoise water.

This gold mine–turned–swimming hole is the perfect summer picnic spot, immersed in nature and history.

Just your average Marie Antoinette–themed speakeasy in an abandoned 19th-century subway tunnel.

A South African bar inside a hollowed out 6,000-year-old Baobab.

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

Nikola Tesla's former home contains an homage hidden from plain sight.

A 115-year-old restored German dining hall awaits those who venture beneath the Minnesota State Capitol.

There's an exclusive Beefeaters pub hidden in the Tower of London.

A secret door leads to this cozy dive that sells only “milk.”

An underground nightclub helped spark a "Singing Revolution."

This beach pool offers a spectacle of crashing waves, blue hues, and a historical lighthouse.

This beachside town is home to a diverse nature reserve, multiple cays, and one of the three bioluminescent bays in Puerto Rico.

Enjoy the waters of this half-moon-shaped natural pool surrounded by breathtaking scenery.

The eerie remnants of an ancient forest were hidden under the sand for centuries.

This last stalwart of the now-forgotten feminist restaurant movement has been serving food in an activist atmosphere since 1977.

Enjoy dishes that founding fathers once ate at this Colonial Williamsburg pub.

The short hike is worth the stunning views and crystal blue waters of a secluded beach.