2300-year-old Roman road connecting the empire.

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

The oldest operating pharmacy in the world features 800-year-old recipes.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

The underground sanctuary of a mysterious ancient cult.

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.

A submerged archeological park still holds the wonders of a Roman Sodom.

Rome's semi-secret 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.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

A 16th-century horror show built in a lovely Italian garden.

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."