The world's greatest slide descends 18 stories from this looping mountaintop viewing platform.

Enormous sandstone towers loom within a Czech forest.

This former quarry is now a picturesque gorge that hides a sunken lake.

A spiral staircase twists to the top of this unusual Czech lookout tower.

Europe's largest natural bridge has a 19th century royal chateau built into its side.

Two monstrous faces loom over a village in Czechia.

An eerie, existential museum dedicated to the author of "The Metamorphosis."

Street artists transformed an abandoned air vent into the beloved Star Wars robot.

A collection of anatomical samples from one of the first anthropologists to suggest that humans reached North America by crossing the Bering Strait.

A steampunk-styled three-floor factory churning out art, activism, and electronic beats.

Walk through Czech history in Prague's largest graveyard.

A church of bones, decorated with 40,000 human skeletons.

A Jenga-style cylindrical tower of books that appears to go on forever.

Two stunning 17th-century libraries and a cabinet of curiosities.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

The walls of this medieval church are covered with perfectly preserved frescos, including a pristine example of the Dance of Death.

A whimsical bridge adorned with decorative dragons.

A line number in Amsterdam that will likely never be used again due to its tragic history.

Europe's official "zero-level," the equator of elevation.

This bronze statue of Martin Luther King was placed in the park without permission.

A unique collection of gilded age mechanical pianos.

This unattributed sculpture in Amsterdam is hiding in plain sight.

Iron Age grave stones and Viking burials, a short drive from Gothenburg.

An "evil painter" included pointed symbols in this artwork to poke fun at members of the Danish Parliament.