Atop this library is one of the most beautiful green spaces in Warsaw.

Order “Proletariat’s Cutlet” at this communist-themed restaurant allegedly once visited by Lenin.

A collection of modern and vintage pinball machines housed in the cellar of a 15th-century building.

Built to transport German U-boats through the never-completed Masurian Canal, the locks near this Polish village are now home to a rope course.

This extensive collection covers thousands of years of Polish military history.

While the U.S. and Soviet Union were engaged in a space race, Poland built a UFO on the ground.

This oddly beautiful water cistern is a techno-temple to the wet stuff and a multimedia masterpiece.

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

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

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

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

This hidden collection of everyday objects illustrates life within communist Poland.

Naturally formed rock city in Poland.

The world’s narrowest house makes for an awkward, four-foot-wide living space.

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

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

This 700-year-old structure is one of the most unique architectural and historic monuments in Gdańsk.

A hidden art gallery in an abandoned Warsaw fort.

A fairytale Gothic castle steeped in Nazi treasure conspiracy theories.

An underground city of salt.

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

Located near Cairo's El Korba district, the abandoned mansion continues to inspire mystery and rumor throughout the city.

The medieval center of the Islamic world was also once the seat of Saladin's sultanate.

A strange aquarium with stuffed fish, and almost no water for them to swim in.