It houses the remains of a 17th-century version of the Titanic.

Sweden's first nuclear reactor, R1, can be visited 25 meters underground.

This colorful artistic feature atop a Danish art gallery allows visitors to stroll through a rainbow.

An ultra-modern diversity park in Denmark has turned an entire city block electric pink.

Bored potato-guarding Nazis etched their thoughts onto a brick storage building in Copenhagen's Meatpacking District.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

New York City's smallest piece of private property.

Those belting out show tunes might not realize this piano bar marks the site where Thomas Paine died in 1809.

The Pope’s secret escape route.

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

A kaleidoscopic warehouse-maze of handmade neon signs.

A decommissioned tube carriage within a London museum hosts a regular pop-up supper club.

A Swedish farm is the world's only producer of the rare, creamy delicacy that is moose cheese.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

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

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

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.

This collection of 80 polarizing foods aims to challenge your subjective notions of repulsion.