One of the oldest masonic temples in the Netherlands, built in 1757.

This artificial ring island was built to hold cubic tons of polluted dirt.

This giant radio telescope would be a rusting ruin if it hadn't become such a beloved relic.

This Dutch statue is a monument to the fictional shrew who brought doom to the city of Stavoren.

One of the great math minds of the 17th century is underfoot in this 900 year old Dutch church.

A massive explosion that leveled hundreds of buildings in the city of Leiden is remembered by a waterside plaque.

A radio telescope for listening to the stars, based in one of the cloudiest countries in the world.

Hop aboard a charming bog train to explore this rare open-air museum of peat.

Now a museum, this building was once a 14th-century monastery and the place where the founder of the Dutch nation lived and was assassinated.

Most complete collection of Gymnosperms in the world.

A set of 27 bamboo tubes creates an eerie soundscape that changes with the wind.

The remains of a medieval wall discovered in the basement of a jewelry store.

The world's longest wildlife overpass provides Hilversum's critters with a safe alternative to trying their luck on the roadway.

Elegant marble and old vaults fill this historic Dutch bank turned office space.

Small transmitter operated by a priest in the Netherlands.

This stately council chamber hasn't changed since 1545.

A miniature train-ride through Slovenia's largest cave system.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

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

This massive subterranean fissure is known as the "underground Grand Canyon."

The "dragon babies" of southeastern Europe.

Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

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

A whimsical bridge adorned with decorative dragons.