Suffocating dogs was a common spectacle in the fumes of this noxious cave.

A climbing route in the mountains of Italy’s Dolomites, built for soldiers during World War I.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

The remains of an ancient Roman city are hidden underneath Bologna's beautiful public library.

This overgrown mountain village has been abandoned for nearly a century.

It’s said this crypt was the setting for the tragic finale of the Shakespeare play.

A line of abandoned, alien-like fortresses dot the mountains of North Italy.

This breathtaking monastery was established by Saint Benedict himself 1,500 years ago.

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

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

This ancient altar emerges from the thick forests to reveal the mysteries of Etruscan sacrificial rituals.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

The burial place of an obscure North African saint was turned into a macabre body preservation factory for the 17th-century Neapolitan elite.

Bell tower juts out from a village buried under a lake.

In the early Roman Empire, people deemed traitors and criminals were tossed to their deaths from this rock.

A burial vault located under Tiber Island in the middle of the Italian capital.

Roman-era ships unearthed...

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

A once-luxurious, now abandoned hotel in the Italian Alps.

This historic recreationist school churns out warriors that may very well have had a fighting chance in Rome's pits of the day.

Rome's ancient Etruscan rival, now a park full of ruins.

Ancient ruins hidden underneath a modern luxury hotel.

Erotic art covers the walls of the largest ancient pleasure palace.

Venice's island of the dead.