This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

Enormous lake at the bottom of a unique cave system.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

Famously misunderstood wonder of the ancient world

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

Notorious artist squat renovated into legal studios.

Try not to get slimed in Tribeca.

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

An enormous, inside-out glass globe built in 1935.

Since 1874, this macabre collection has developed into a museum devoted to Scotland Yard's mementos of dastardly deeds.

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

An Australian lake whose pink hue defies scientific explanation.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

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

An exquisite tunnel of cascading flowers.

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

A magical place that lets you play in and explore the world of Studio Ghibli.

A church of bones, decorated with 40,000 human skeletons.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

New England's tallest light house stands on an island with a history of cannibalism and death.