Ruins of a 10th century church tucked away deep in a botanical garden.

A 16th-century horror show built in a lovely Italian garden.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

This Denmark theme park is part family attraction, part experimental archaeology project.

Vortex-shaped aquarium hosts Europe's largest school of piranhas and other ocean creatures.

A 19th-century subterranean reservoir repurposed as a contemporary art cave.

This small window display is dedicated to the noble carrot.

These crumbling Nazi artillery bunkers are now fair game for massive graffiti projects.

Tucked away in the Leiden city hall are a group of works by famed artist MC Escher.

Hidden within a Netherlands crater is a stone bed that lets those who lie in it see the sky as a curved surface.

The tallest waterfall in the Netherlands is a lovely, stepped feature that is only 50 feet tall.

This disused VLF radio station is no longer in service but the surrounding town still bears its name.

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

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

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

A magical and peaceful ruined Cistercian abbey in what is now southern Belgium.

Medical history with an amazing, if frighting, collection of wax diseases on display.

A giant bug impaled on a 75-foot-tall needle.

Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.

A monument hidden in the woods built in 1938 as a getaway for a Dutch museum curator.