The abandoned "Red Star Train Graveyard" is the final rusting place for precious artifacts of train history.

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

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

The final resting place of the last "gypsy king" of Poland.

In northeastern Poland, the ruins of a massive granary overlook the Narew River.

A hidden art gallery in an abandoned Warsaw fort.

The final resting place of more than 200,000 people, this is one of the largest cemeteries in Europe.

This enormous 32-foot painting depicts Poland's greatest medieval battle in glorious detail.

One of the world's largest collections of medieval religious art.

A statue honors the children who fought Nazis in Poland.

These 18th-century paintings of Warsaw were used to reconstruct the city after World War II.

A program of Communist glamour in post-Stalin Poland is preserved in this colorful museum.

Once known throughout Europe, this tiny and unusually progressive 18th century micro-nation within Lithuania now lies in ruins.

Legend has it that Napoleon Bonaparte fell in love with this Gothic church.

Things aren't quite what they seem at this mind-bending museum.

A century-old prison in the heart of Vilnius is now a lively bar, dance club, and artist residency.

Poland's oldest salt mine has nearly everything one needs to live underground forever.

Sculpture garden of religious statues made it through Soviet rule.

Launch site for nuclear war against Western Europe.

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

The Habsburgs' royal collections of art and wonders.

A neo-Gothic mansion now houses a wunderkammer of analog tech that hits on all the senses.

Slovenia's first mosque is a striking mix of Islamic and modernist architecture.

Strange rumors surround the artist who created these solemn metal guard dogs.