A hidden three-foot-wide house separates these two regal churches.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

A dreamlike medieval church dug into the tuff rock, with unusual carvings and possible traces of the Templar knights.

This sword isn't waiting for a king to pull it out. It was placed there by a saint.

This real life asylum of horrors is now an abandoned ruin that hides the unbreakable code to one patient's insanity.

Medieval torture techniques with a modern conscience.

The relics of dozens of martyrs are stored in a single chapel.

The remains of the left arm of the levitating philosopher-saint are kept in a 13th-century Neapolitan basilica.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

The Vatican's secret porn-festooned bathroom was painted in erotic murals by one of the greatest artists of the Renaissance.

San Gennaro, the patron saint of Naples, greets pedestrians between these narrow city streets.

A popular legend claims that the famous pizza was invented at a restaurant in this alley.

Every day is like Christmas on this street where the traditional Neapolitan nativity scene comes to life.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

This magical-looking island is notorious for the misfortunes suffered by its owners.

This shining multicolored metro station deep under Naples is said to be the most beautiful in Europe.

Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

Ever hear of the Milazzo Cage?

Rome is now home to a stunning food museum and library.

According to local folklore, this Roman sepulcher was once a throne for the Devil.

A massive marble foot is tucked away in a small alley near the Pantheon.

Hidden within this iconic mountain are a set of World War II bunkers once used by German forces.