An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

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

An unusual number plate signifies the building's saucy past.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

This mural painted by Keith Haring was done without payment as a gift to entertain the children at the Hôpital Necker.

The narrowest street in Paris.

This recessed garden protects thousands of mountain plants by creating its own microclimates.

Two awe-inspiring globes from the reign of the Sun King hang from the ceiling of France's national library.

Ordinary art transforms to extraordinary thanks to locals' quirky sense of humor.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

This emotive sculpture was originally created for the 1878 World's Fair.

Behind the pink curtain, Au Bonheur du Jour, an art gallery of erotic archives.

Claude Monet was baptized in this lavishly ornate Paris church.

BDSM, 1930s Style.

Inside a former cabaret, seven floors of erotic art.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

The video game-themed street art first popped up in the French city.

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A museum dedicated to the history & joys of the trail & your best chance to see hikers throwing up ice cream.

An almost life-sized elephant named Ms. Ellie greets visitors at this jumbo-themed museum.

A diorama of the Civil War, fought by cats.

Conflicting markers on its floor tell a tale of two city centers in San Antonio.

This big empty pig is a nostalgic throwback to mid-20th-century Texas barbecue.