This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

An encyclopedic collection of mammal penises.

A wonderfully strange collection of 500+ stuffed frogs doing people things.

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

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

A surreal statue honoring Prague's favorite literary son.

The palace window through which Protestant nobles flung two Catholic regents, thus sparking the Thirty Years' War.

A crucified and bearded female saint.

Looming communist pillar with a Czech twist.

One man's personal collection of KGB memorabilia is presented along with his strange viewpoint.

Microscopic scenes; some call it novelty, some call it art.

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.

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

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

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

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

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

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.

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

Finland's oldest astronomical observatory once played a crucial role in seafaring and timekeeping.

A rare octagonal brick beacon on an isolated island in the Baltic.