The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

Mountain where Jesus was first tempted by the Devil.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

Notorious artist squat renovated into legal studios.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

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

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

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

Erotic art covers the walls of the largest ancient pleasure palace.

Ancient snack bar of the Roman Empire re-opened.

Every day is like Christmas on this street where the traditional Neapolitan nativity scene comes to life.

Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

This shining multicolored metro station deep under Naples is said to be the most beautiful in Europe.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.