Jesus' footprints and the first catacombs in the world.

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

The final resting place of the poets Shelley and Keats.

2300-year-old Roman road connecting the empire.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

The middle finger of modernity.

An alchemist's “magic door” stands in the middle of a Roman park.

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

Rome’s legendary peephole vista is also a former Crusader stronghold.

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

Architectureal fantasy quarter of Rome.

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

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

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 mountain trail inspired Nietzsche to complete his magnum opus.

This triumphal arch celebrating the Sun King's conquest of Lille is a masterpiece of military architecture.

If you look closely at the oldest bridge in Paris, you might notice hundreds of ugly faces leering from its sides.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

The encased skull that is widely believed to belong to St. John the Baptist.

This futuristic observatory at the top of the Pyrénées offers unrivaled views.

One woman's decades-long obsession with the "La Fée Verte."

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

The only remaining collection of flayed figures made by French "madman" Honoré Fragonard.