A museum of carnival attractions where you are invited to ride the rides.

Paris' linguistic guide to the international language of, yes, love.

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

A haunting collection of the vanished and disappearing natural world.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

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

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

A fairy tale castle in modern Rome.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

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

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

Architectureal fantasy quarter of Rome.

The yawning maw of this pagan visage is said to bite off the hands of liars.

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

The famous abolitionist’s preserved estate is one of Washington's finest monuments to its great Black citizens.

They sort through millions of dollars worth of diplomatic gifts on behalf of the government.

Where the U.S. government kept its actual treasure, before Fort Knox.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

Does this strange mural depict witches battling beneath a penis tree?

You could be standing at the site of one of D.C.'s most fatal tragedies and not even know it.

This leafy estate is worth $18 million and is so grand it has two mailing addresses.

The school tested mustard gas for the U.S. Army during World War I.