This graffitied 19th-century building was a prototype of European industrial architecture.

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.

Legend says it was constructed with the destroyed pillar of an ancient Greek Temple.

This historic structure has been used as a mosque, a barracks, a prison, a school, and a bakery.

This slumbering beast honors the Bavarian soldiers who died in Greece during a 19th-century typhoid outbreak.

Preserved portions of Athens's ancient defenses are on display in a subterranean parking garage.

This 18th-century former mosque held the first Hellenic Parliament.

This cheese shop also houses a museum devoted to Dutch dairy.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

A UFO-shaped event building originally intended to be a science museum showcasing the future.

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

Sofia's legislative center is continuously reinventing itself.

"Holy Wisdom" overlooks the city that became its namesake.

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

A striking symbol of the Bulgarian capital.

This building has two facades of clashing architectural designs.

The ruins of this ancient fortification wall sit in the middle of a quiet, residential intersection.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

An often overlooked ancient site in downtown Athens with substantial history (and nature).

Once a 19th-century brasserie, this McDonald's exterior celebrates Alsatian design and the "King of Beer."

A tiny Greek Orthodox church from the Ottoman era hides on a busy city street.

Underneath one of the region's most historic roads lies the home of Plato's successor.

Now a museum, this building was once a 14th-century monastery and the place where the founder of the Dutch nation lived and was assassinated.

The spectacular history of spectacles on display.