A labyrinth hides in plain sight at each of the city's 270 Tube stations.

Where the dead once lay, art now plays.

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

This stunning iron gate designed by Modernist architect Antoni Gaudí is filled with mythic symbolism.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

One of Europe's largest supercomputers is housed inside of a disused chapel.

Designed by Gustave Eiffel before his famed tower.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

This stunning mass of ice spans 121 square miles and is still growing.

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

A grumpy old water goblin guarding an old mill on the Devil’s Stream in Prague.

This moving sculpture depicts contortionist positions based on photographs of gymnast Věra Čáslavská, who protested the Soviet invasion of Czechoslovakia.

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

A beautiful window with the old Tesla Radio company logo.

Nine bronze hands protruding from a wall honor the student uprising that led to the fall of Czechoslovakia's Communist government.

One of the famous Czech artist's lesser-known Prague installations appears to be a glowing fetus affixed to a drainpipe.

This Czech church doubles as something of a permanent fashion exhibition for a statue of the Infant Jesus.

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

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

A turn of the century building boasting some of the most beautiful art nouveau architecture in Prague.

What looks like a suicide in progress is actually a statue of Sigmund Freud.

The largest and best-preserved rotunda in Prague.

A rooftop restaurant hides in plain sight atop Vienna's Palace of Justice.

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