This curious, round temple is the oldest still-standing marble building in Rome.

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

Architectural monsters are devouring this palace's every door and window.

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

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.

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

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

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

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

Known as the "Dodo Manège," this carousel features a herd of animals that have disappeared—or may be gone soon.

Down a cobblestone alleyway is a museum dedicated to Romanticism, with a secret garden.

A Parisian exterminator's shop whose storefront displays stuffed rats hanging from traps.

How did a French journalist’s grave become the sexiest statue in the cemetery?

A mechanized clock where a man fights off a dragon, crab, and rooster.

A surrealist timepiece by the artist of melting clocks.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

A counter-culture bookstore like no other hides in plain sight in the streets of Paris.

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

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

Notorious artist squat renovated into legal studios.

France's most famous cemetery, with some of its most curious tombs.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

Christ's blood preserved in a Belgian town.