The amazing wonder cabinets of a very rich Austrian archbishop.

An Austrian house of bones filled with hundreds of intricately painted skulls.

The world's oldest known salt mine.

A public work of art that also provides some relief from the summer heat.

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

A relic from the Industrial Revolution got a second life as a contemporary performing arts space.

A whimsical bridge adorned with decorative dragons.

A trough of 700 strange bronze faces runs through a narrow alley in Ljubljana's old town.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

A wonderfully strange collection of 500+ stuffed frogs doing people things.

The big toe of this towering monument to a Croatian national hero is worn from years of superstitious rubbing.

When a supermarket opened up shop within a medieval building it became protected by UNESCO on a technicality.

Formerly Yugoslavia's "forbidden island," this sleepy little city still holds the abandoned remains of military strongholds.

When Croatia became independent of Yugoslavia, the splintering governments left behind these concrete tunnels.

Longest fortress system anywhere in Europe.

This 15th-century church houses priceless works of art from a range of Croatian artists.

An ancient knight and a symbol of the city's freedom.

Gargoyle head that brings good luck.

A full figure 4th century incorruptible saint lies in a glass coffin in Croatia.

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

The Netherlands' first car tunnel has an unusually rectangular shape.

Birthplace of the "Cat in the Cradle" and a cluster of iconic, original windmills that let the Dutch tame the seas.

Take a stroll through the hellish grotesques of Hieronymus Bosch in this elaborate Netherlands church.

This medieval castle was painted pink as part of a now-abandoned children's theme park.