A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

The yawning maw of this pagan visage is said to bite off the hands of liars.

In the middle of a Vienna square, Roman ruins dating back some 2,000 years are on display.

The holes in this wall provide a glimpse into Jewish life in Budapest, both past and present.

This giant Cold War satellite dish has become a symbol of Trinidad's need for sovereignty.

A fragment of one of history’s most famous walls stands as a reminder of unity in a culturally divided city.

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

An Italian hillside ghost town.

Geometry and mystery come together in an epic show of octagonal masonry.

The Emperor Tiberius' palace of debauchery.

A cave in southern Italy adorned with thousand-year-old Biblical frescoes existed in obscurity until fairly recently.

People have been living in the cave houses on this Italian hillside since the Neolithic era.

One man's quest to fix his toilet unearthed over 5,000 artifacts spanning more than 2,000 years of history.

A long-buried ancient ruin unearthed right in the middle of the city.

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

An abandoned 17th-century baroque hunting lodge with a wonderfully strange architectural plan.

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

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

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

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.

An ancient Roman temple first dedicated to an emperor's wife is now a church.

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