These medieval tunnels provided water to the city above through centuries of civil war and plague.

Tourists to the mountaintop Sicilian town often overlook its ancient fortifications.

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

Three underground crypts and a pointed arch under the bell tower make this cathedral unique among Romanesque churches.

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

A 1,000-year-old church holds the bones of the Christian martyrs who died hiding inside it.

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

This 10th-century seaside abbey holds spectacular views and a window into the past.

Pompeii's less famous neighbor is still revealing her secrets.

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

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

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

A 2,000-year-old engineering wonder hides beneath an Italian town.

What appears to be an ancient Roman temple is actually a Catholic church.

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

Take a giant yellow bird cage to the top of Elba's highest mountain.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

Next to the Leaning Tower of Pisa is a cemetery home to ancient sarcophagi and disturbing murals.

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

This Renaissance palace features a unique architectural design and is now home to the Ferrara National Art Gallery.

One of the earliest depictions of an Arthurian scene that is shrouded in mystery.

One of the oldest and most significant collections of Ancient Egyptian archeology outside of Egypt.

Da Vinci's equestrian statue, 500 years in the making.