A dead saint, a deadly poison, and a mysterious holy ooze.

A Jenga-style cylindrical tower of books that appears to go on forever.

Legend says this mysterious stone head belongs to a woman who was petrified by an alchemist.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

Former military fort and site of untold horrors during WWII, this island may become the Adriatic's next luxury resort.

This exclusive resort has completely covered a tiny Balkan island in a 5-star warren of guest rooms.

A tiny church on a man-made island in the Adriatic.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

The plague quarantine island home to the alleged "Vampire of Venice."

The remains of this 2nd-century Roman temple are incorporated into a modern building.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

Romans decided this 16th-century "talking statue" was so ugly, they named it after a primate.

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

The first Russian Orthodox church in the Catholic city of Rome in almost a thousand years.

This is the oldest Roman-made bridge in the city still existing in its original state.

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

This ancient market is often referred to as the oldest shopping mall in the world.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

A magnificent waterfall is also home to the remains of a Roman hydraulic engineering system.

This large, circular tomb is the final resting place of the first emperor of Rome.

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

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

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

The curios of pharmacist and collector Henry Wellcome.