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.

A perfectly circular lake is formed by the crater of an ancient underwater volcano.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Macabre astrological automaton clock dating to the late 1400s.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

The beautiful baroque library of the Hapsburg empire.

A neolithic tomb converted into a tiny chapel.

The "Little Ones," show Portugal in full miniature splendor.

One of the largest Roman settlements in Portugal.

"Portugal's Stonehenge" is made up of nut-like stones aligned with the heavens.

This crumbling Portuguese ruin overlooks the populace it once ruled.