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

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

Once the home of a hermetic monk, this cave now houses a small church.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

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

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

The last municipal pneumatic post system in the world was in operation for over 100 years, and may run again.

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

A saintly relic hidden in a Prague church basement.

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

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

A collection of anatomical samples from one of the first anthropologists to suggest that humans reached North America by crossing the Bering Strait.

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.

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

Macabre astrological automaton clock dating to the late 1400s.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

A statue honors the children who fought Nazis in Poland.

An artificial hill and apparent calendric structure built in the Early Middle Ages immortalizes a legendary Polish princess.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

A national collection of Communist-era musical posters.

This sprawling concrete suburb of Kraków was designed by the Soviet Union as the model proletarian city.

Poland's oldest surviving university building holds a wealth of historic science instruments including some used by Copernicus.

The unsettling remnants of a torn down movie set lies nearby the ruined location of the actual Płaszów Labor Camp.