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

A national collection of Communist-era musical posters.

A peculiar family mausoleum built by a German nobleman captivated by the occult.

A 20th-century picture show in 3-D.

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

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

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

Naturally formed rock city in Poland.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

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

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.

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

Warsaw's fantastically preserved gasworks...almost.

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.

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.

This uber-quaint Polish village is known for its habit of painting elaborate floral motifs on just about everything.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

A fairytale Gothic castle steeped in Nazi treasure conspiracy theories.

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

This Polish cave has housed a dragon, a brothel, and an enduring legend.

The site of the first battle of World War II.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.