The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

A battle between nature and architecture in the Cambodian jungle.

A serpentine highway twists and turns over the treacherous Norwegian Sea.

An island filled with hundreds of hanging, decomposing, decapitated dolls.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.

An Australian lake whose pink hue defies scientific explanation.

The largest of London's subterranean rivers and once a mad, bad center of London life.

A seemingly endless landscape of pure salt stretches far across Bolivia.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

The real life Hobbiton, this sheep farm has been forever transformed since being built for The Hobbit film series.

A swing to dangle you off the very edge.

Medicinal spa created with the discharge from a geothermal energy plant.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

Most-visited and most-photographed slot canyon in the American Southwest.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

A fiery crater has been burning in the Karakum Desert since 1971.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

Rippling sand dunes frozen in the Arizona rock.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

There are thousands of tributes and memorials to the King, but none quite like this one in a Kraków city park.

Poland's oldest salt mine has nearly everything one needs to live underground forever.

Boats must transform into railroad cars to navigate this Polish canal.

Countless stories attempt to explain Poland's mysterious J-shaped trees.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.