A controversial artwork draws attention to the dark history of Prague's "Suicide Bridge."

Bullet holes in the church wall are a reminder of the violence that followed the assassination of a high-ranking Nazi officer.

A surreal statue honoring Prague's favorite literary son.

A series of playful yellow penguins share a serious message about the environment.

Enormous sandstone towers loom within a Czech forest.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

The deepest sinkhole in Central Europe comes with a grisly tale and an unusual nickname: “The Stepmother Abyss.”

Increasingly decayed figures stand as a powerful reminder of the human costs of Czech Communism.

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

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

Bohemian paradise covered in majestic forests.

What looks like a crashed Zeppelin is actually a bright, airy reading room perched atop a modern museum.

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

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

This artificial cave looks like something out of a fairytale.

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.”

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

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

Macabre astrological automaton clock dating to the late 1400s.

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

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

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.