Copenhagen's celebrated theme park and gardens.

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

This equestrian statue of Constantine the Great has been the subject of criticism for centuries.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

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

The only Shinto shrine in Europe that has been officially sanctioned by Japan.

Believed to be the remains of the lost Temple of Minerva, this nymphaeum has been known by its misnomer to this day.

This amazing medieval fortress stands atop a promontory along the famous Cinque Terre.

Known for centuries as the famous Roman emperor's burial place, this monument is actually something else.

According to tradition this is the oldest church in Venice, but its actual age is a mystery.

This is the oldest Roman-made bridge in the city still existing in its original state.

Also known as the Temple of Poseidon, this is one of the best-preserved Greek temples in the world.

This medieval mountain town is also known as the "Village of Streams."

The pristine waters crossing this forest form a hidden waterfall among the dense vegetation.

A magnificent waterfall is also home to the remains of a Roman hydraulic engineering system.

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

The sunlight passing through the opening of this huge cave system creates a magical effect.

The bright red cars take travelers through breathtaking Tuscan scenery.

A copy of the famous statue can be found in this Florence piazza, along with one of the most breathtaking views of the city below.

This park on the outskirts of Rome boasts two ancient Roman aqueducts and a medieval tower.

The first botanical garden, a feather in the cap of the Grand Duke of Tuscany.

Nestled in the hills of Tuscany are gorgeous, multicolored hot springs.

Ride a boat through this magnificent underground world, which now doubles as a theater.

A slightly creepy gallery of plaster cast models in the same museum as Michelangelo's David.