Spain's largest bullring offers a unique glimpse at architecture and history.

This artistic fountain display pays homage to this area's theatrical history.

A room filled with frescos that make it seem like the walls are crumbling down while giants die in despair.

It took more than 300 years to build this church, which is home to two sacred vessels believed to hold the blood of Christ.

One of the tallest bell towers in Italy plays a particular melody at just two times each day.

The origins of a large, medieval castle are shrouded in mystery, but now it's a delightful garden.

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

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

A large statue of Pope Gregory XIII in Bologna was disguised as Saint Petronius to avoid destruction.

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

The intricate geometry inside this Baroque-style dome was designed to create "terror of the human soul."

This Ottoman-era church is hidden amid a busy tourist area.

One of the most well-preserved castles in Italy also contains a rare medieval example of a port fortification.

A medieval castle was used for centuries as a hemp farm.

The giant skeleton sculpture is surprisingly well-traveled.

This hydrochronometer was invented by a Dominican monk and is a prime feature in this garden.

This uniquely designed bridge served as the city gate for Comacchio.

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

Once home to one of the oldest banks in the world, this building is also where Marco Polo's famous travelogue was written.

This Renaissance square was at the center of Leonardo da Vinci's map, the first ichnographic ever.

Ancient catacombs form the foundation for this Rococo orgy of a church.

An abandoned monastery sits on a far-off island in the Adriatic Sea.

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

This seaside Italian village doesn't just look Escher-esque, it actually inspired the mind-bending artist.