A black cat protests the City Guild in Riga's Old Town.

The statue of a legendary giant who carried Christ and shouldered the world's sins.

3,000 market stands in five former Zeppelin hangars.

Medical museum that houses most notably the taxidermied remains of Vladimir Demikhov's famous two-headed dog experiment.

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

The medieval town's star-shaped walls are geometrically dazzling, though not entirely impenetrable.

Go inside to really appreciate this 500-year-old technological masterpiece.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

Austria's ultra-modern art museum looks like Cthulhu's giant alien heart.

Double spiral staircases are not unheard of, but they are very rare.

This one-time health resort was used by aristocrats around the world.

A whimsical bridge adorned with decorative dragons.

This abandoned Slovenian military barracks has become a punky-political art squat.

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

Sculpture of a legendary French dragon.

Even France's favorite aquatic son Jacques Cousteau, couldn't get to the bottom of it.

Historic medieval fortified city in southwest France.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

The final resting place of the great navigator, or maybe his brother.

Geological storytelling.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

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

Picturesque intersection of witchcraft and ancient Christianity.