The world's largest "Christmas tree" is illuminated by hundreds of lights stretching 2,000 feet up the slope of Mount Ingino.

Italy's third-largest Roman arena gives a peek into the underground operations beneath the ancient spectacles.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

This amazingly preserved Doric temple was abandoned before it was ever completed.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

An abandoned quarry hides an open-air gallery of huge sculptures, some made from the rubble of 9/11.

The underground sanctuary of a mysterious ancient Roman religious cult contains an exquisite traditional fresco.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

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

A tree that defies gravity grows in an ancient ruin.

A fascinating assortment of cave dwellings, medieval ruins, and sarcophagi are being devoured by the forest.

Centuries ago, red and white wine poured from the statue's breasts whenever a new Venetian ruler was elected.

The bones of some 7,000 soldiers killed in the historic Battle of Solferino are stored here.

The walls and streets of the ancient city are peppered with penises.

Fountain where visitors can earn a license to be mad.

Ancient ruins hidden underneath a modern luxury hotel.

The naturally mummified body of a peasant girl saint.

142 ceramic steps become a mosaic once a year.

This military mausoleum captures the solemn grandeur that most memorials only aspire to.

Fortified medieval tower house with lovely roof garden.

Water and windows define this defensive Italian well.

A star-shaped fortress town fort built in the geometric model of the Renaissance utopian city.

These gutted monastery ruins still stand proudly in the middle of the Italian countryside.

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