The world's most active stratovolcano is almost always erupting.

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

Secret refuge and museum of the Duke of Florence.

A volcanic old faithful, Stromboli has been erupting continuously for the last 2000 years.

These medieval skyscrapers dominate the skyline of this small Tuscan town.

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

This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

A Nesting Doll of Churches.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

Jesus' footprints and the first catacombs in the world.

A dismembered holy head stares out from her beautiful reliquary at the St. Dominic Basilica.

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

2300-year-old Roman road connecting the empire.

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

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

The once forbidden "secret cabinet" of erotic art from excavations of Pompeii and Herculaneum.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

A classic advertising icon immortalized in regal bronze.

Shoot for par over the bodies of the dead on this cemetery-cum-golf course.

An enormous artwork that colorfully celebrates over 150 years of US military achievements.

The taxidermied remains of the "last wild grizzly bear in California" and of the symbol of the state of California.

Once the largest windmill outside of Holland, with enormous 114 foot sails.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.