Historic medieval fortified city in southwest France.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

One of the world's tallest Ferris wheels takes visitors high above Las Vegas in a spinning party room.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

Hundreds of hidden passageways weave through the old quarters of Lyon.

Medical and zoological curiosities for sale.

James Turrell's total color immersion art installation, hidden on the top floor of a luxury handbag shop.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

An eerie, derelict amusement park in Berlin.

A cave dwelling that was started by the Celts, expanded by monks, and finished by knights.

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

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

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

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

World's largest collection of serial killer artwork and other macabre exhibits.

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

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

These fantastically named natural pools look like something out of a Scottish myth.

What is the Thing?

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

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

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

A museum of magic with a Sadist past.