The beautiful baroque library of the Hapsburg empire.

A merchant court dedicated to the fictitious King Arthur is heavily adorned with bizarre Renaissance art.

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

This towering statue of Jesus provided internet to the surrounding area.

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.

This fairytale medieval church in Poland originally spent centuries in Norway.

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

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

An underground city of salt.

Countless stories attempt to explain Poland's mysterious J-shaped trees.

Extremely famous in his native country, this Cracovian painter is all but unknown beyond Polish borders.

Inside this Krakow church, an explosion of psychedelic color.

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

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

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

Futuristic apartment blocks are the backdrop for Montreal surfers hangin' ten on the Habitat '67 standing wave.

A fairytale Gothic castle steeped in Nazi treasure conspiracy theories.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

This "floating railway" is one of the world's oldest monorail systems.

In an isolated field near a dilapidated barn stands this chilling portrayal of the plight of the Nuba peoples of Sudan.

Walk into the 19th century without leaving Brooklyn.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.