An alchemist's “magic door” stands in the middle of a Roman park.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

A cablecar-station-turned-revolving restaurant with 360-degree views of the Swiss skyline.

The second-highest train station in Europe.

A historic observatory precariously perched at the "Top of Europe."

Caves famous for the dragon-slaying saint who lived there.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

A copy of the Statue of Liberty greets visitors to the birthplace of Auguste Bartholdi.

Visitors dating back to the 1600s carved their marks in the stones of the iconic tower.

Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

This 14th century wine cellar is home to the oldest barrel-stored wine in the world.

There has been an astronomical clock on this spot since the 14th century.

The castle was reconstructed to fit Kaiser Wilhelm II's romanticized vision of the Middle Ages.

An immersive projection art installation uses sound, scale, and light to take visitors inside classic works of art.

The tomb of history's greatest potato promoter is surrounded by tubers.

France's most famous cemetery, with some of its most curious tombs.

The final resting place of the "father of special effects."

How did a French journalist’s grave become the sexiest statue in the cemetery?

An early 19th-century English style garden hidden in the Rotterdam cityscape.

You would never come across this tiny green oasis if you didn't know it existed.

You can spot this teeny tiny stained-glass window from the Bonifacius bridge.

An unsettling sculpture of a boy hanging out in a street in Ghent has been baffling visitors for years.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.