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

An underground city of salt.

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

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

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

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

In the center of Wrocław's old meat market stands a somber tribute to the city's livestock.

Relive a Polish uprising via an enormous, century-old cyclorama.

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

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

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

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

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

Architectureal fantasy quarter of Rome.

Architectural monsters are devouring this palace's every door and window.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

A beautifully eclectic mix of architectural styles.

Amsterdam's Red Light District leaves little to the imagination.

Amsterdam's narrowest house facade is a monument to 17th-century tax evasion.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.