Where lovers tie birch branches into long-lived knots.

An impressive array of unique homemade planetariums.

This ghost town in Belgium will lose its street art when it ceases to exist.

A former ironworks that was the first UNESCO industrial site.

An amusement park on the grounds of an unused nuclear power plant, with a swing ride inside the cooling tower.

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

Inspired by "The Starry Night" this Dutch bike path turns into a glowing work of art each night.

A UFO-shaped event building originally intended to be a science museum showcasing the future.

Crouch down, stretch tall, and be sure to flail your legs to pay homage to the Monty Python classic.

A rare double mill nestled along the banks of the Aa river.

Unchanged for centuries, this medieval library keeps its books in chains.

This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.

The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

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

Its town washed away centuries ago, this lonely tower by the sea tells the tale of a mermaid and a curse.

One of the largest burial mounds in the Netherlands and Belgium.

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

This large sand dune in the Netherlands is home to wind-whipped trees with "floating" roots.

At the base of this tower, a plaque marks the original center point of the Netherlands.

This gigantic monument hidden in the woods was built to thank the Dutch for sheltering Belgian refugees during World War I.

A grassy pyramid named after a French battle.

A dream-like maze full of strange art, surreal spaces, and fantasy landscapes to get lost in.

The "stairway to heaven" lookout tower was built to resist weather, arson, and the laws of physics.

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.