This open-air museum was originally a World War II testing ground for German missiles and rockets.

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

This 13th century Gothic brick castle is the largest in the world by surface area.

One of the largest amphitheaters in Europe is a former Nazi gathering place that still stands today.

An abandoned Jewish sanatorium is tucked within the woods of Poland.

A 90-ton, gravity-defiant steam locomotive shoots for the skies in this bizarrely beautiful public artwork.

The hollow trunk of this 650-year-old tree was used as a hideout by two Jewish brothers during World War II.

A floundering Polish shipyard was once the soul of the Solidarity movement that capsized communism.

A World War II torpedo launch station abandoned off the Polish coast.

Deep in a Polish forest, this collection of Iron Age megaliths still holds onto many of its ancient secrets.

Boats must transform into railroad cars to navigate this Polish canal.

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

A haunting deserted hotel is a favorite with artists and photographers.

This imposing 20th-century castle was abandoned before it was ever completed.

A mysterious structure left behind on the Polish mountainside, sometimes called "Hitler's Stonehenge".

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

A huge wooden clock that is so beautiful its creator was forcibly blinded.

These massive moving sand dunes have swallowed an entire village and are still on the run.

An abandoned Nazi explosives plant founded by the inventor of dynamite is now an underground museum.

Naturally formed rock city in Poland.

This man-made mound monument was built out of soil from all across the Polish empire.

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

After the famous composer died in Paris, his sister snuck his heart out of the country to honor his wish that it be buried in their native country.

Communism's topsy-turvy effect on Poland has been brought to life in this wacky tourist trap.