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

Mummified monks and the accidentally interred, in a 17th-century crypt.

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

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

Bohemian paradise covered in majestic forests.

A museum of alchemy and a basement laboratory all housed in an ancient building in a Gothic tower.

This doorless 20th-century elevator doesn't stop or slow down.

This artificial cave looks like something out of a fairytale.

Thirty creepy ghosts now inhabit this decaying 14th-century church.

The tunnel's elegant proportions keep you snug with no claustrophobia freak-out.

Europe's second largest ossuary wasn't discovered until 2001.

An old asylum graveyard that's been abandoned for half a century attracts those seeking a dark thrill.

Underneath this small church are 15,000 bones, arranged by an obsessive academic.

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

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.

The first museum in the world devoted to sexual gadgetry.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Walk through Czech history in Prague's largest graveyard.

Countless grotesque faces stare out from this eerie Prague art wall.

The hidden lair of an alchemist rediscovered in a 2002 flood.

Macabre astrological automaton clock dating to the late 1400s.

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