A narrow strip of land is home to the tallest migrating dunes in Europe.

One of the last remaining railway viaducts equipped with a transporter ferry.

Down this yellow brick road, visitors are treated to toadstool houses and massive mushroom sculptures.

Considered the birthplace of the Copper Age and Bronze Age, the river is tinted red from 5,000 years of mining.

The world's largest wooden structure.

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

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

This quaint Spanish village agreed to be painted blue as a marketing stunt but found that they preferred it that way.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

Rare karst landscape eroded from a flat seabed.

A hidden medieval crypt where a famous legend says the devil used to teach black magic.

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

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

The only remaining U-boat that is still floating never actually saw any action in World War II.

Once the longest swing bridge in Europe.

Constructed by forced laborers, this submarine pen is now a museum and war memorial.

Böttcherstraße's bells, extolling Nordic virtues and the great conquerors of the world.

A stunning gilt bronze relief denounced by Hitler as "degenerate art"—even though it was dedicated to the Nazi leader.

One of the oldest wine cellars in Germany is now a restaurant beneath Bremen's town hall.

A spitting ode to a German serial killer.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

For over 300 years this little carving has been the city’s good luck charm.