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

This fairytale inspired, warped building houses restaurants, shops, and a radio station.

A striking public sculpture representing the period of martial law in Communist Poland.

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

A delightful museum entirely dedicated to the tiny homes of dolls.

The silly symbol for an underground protest group is now scattered around the city.

Crosses of all shapes, sizes and colors litter the mountain, the site of a huge yearly Orthodox pilgrimage.

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

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.

A collection of old neon signs from all over Poland line a secluded courtyard.

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

A national collection of Communist-era musical posters.

A menacing statue of this mythical creature can be seen at the legendary site of the monster's lair.

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

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.

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

Warsaw's fantastically preserved gasworks...almost.

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.

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

The site of the first battle of World War II.