This enormous censer uses a pulley system installed over 400 years ago.

This stop on the Camino de Santiago stands high above the underwater ruins of a medieval town.

Relive a Polish uprising via an enormous, century-old cyclorama.

The silly symbol for an underground protest group is now scattered around the city.

A striking public sculpture representing the period of martial law in Communist Poland.

A fairytale Gothic castle steeped in Nazi treasure conspiracy theories.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

This antique thermometer honors the creator of the first universal temperature scale.

These rare statues are one of the few remaining material witnesses to Old Prussian culture.

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

Now harmless, this looming post struck fear into the heart of medieval troublemakers.

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

This former estate of a fascist leader is now a burnt out ruin leading to a system of secret tunnels.

Yugoslavia's biggest underground airport lies in ruins.

A musical instrument played by the sea.

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

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

There was a top secret plan during World War II to seal a group of soldiers inside the rock.

Hauled from the water's depths, Henry VIII's flagship is preserved in this capsule-shaped museum.

This striking observation tower shaped like a spinnaker sail is the newest icon in historic Portsmouth.

A miniature village mimics the surrounding buildings so well it includes itself.

A lush indoor jungle fills this bustling Madrid transportation hub.

The Great Fire of London and the regulation of one-way streets both started in this alley.

The commemorative stone column conceals a secret laboratory.