The haunting ruins of a military fortress turned astronomical observatory sit on a Sarajevo mountaintop.

This magnificent museum claims to house the cranium of a disciple and the skull of a pope.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

A fearsome dragon clings to a corner of Munich's city hall.

Go surfing on this urban wave, "hacked" by local surfers.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

The patron saint of spinsters grasps a container of dried blood.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

This spooky statue sits outside a famous Prague theater.

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

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

Monument to a suicide protesting the Soviet invasion.

Looming communist pillar with a Czech twist.

This automated sculpture of two men peeing will spell out text messages with their micturition.

A mocking tribute to the past and modern leadership of Prague.

The risqué mixed-media sculptures are supposedly a metaphor for Czech politics.

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

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

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

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

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

A plaque marks the spot where the saint was shoved off the Charles Bridge and into the river.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.