Rome's semi-secret peephole vista is also a former Crusader stronghold.

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

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 ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

A Nesting Doll of Churches.

Architectureal fantasy quarter of Rome.

A fairy tale castle in modern Rome.

A map of Italy made entirely of trees.

An extraordinary collection of 18th century anatomical waxworks.

This zoological museum began as the first great curiosity cabinet.

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

This Tuscan lake hides a 13th century town that is still visible when the water recedes.

The naturally mummified body of a peasant girl saint.

This natural gas vent certainly earns its name as the smallest volcano in Italy.

Sitting on an Italian hilltop is this surreal fortress built by the mad inventor of electrohomeopathy.

A dismembered holy head stares out from her beautiful reliquary at the St. Dominic Basilica.

On rare days, this abandoned castle's gatekeepers open its doors, revealing the eye-popping splendor hidden inside.

The middle finger of modernity.

The mummified relic of St. Antoninus.