This artificial cave looks like something out of a fairytale.

After being destroyed by two separate fires, this monastery is now home to a small zoo and relics from dozens of saints.

In one of the smallest countries in the world stands an original Salvador Dalí sculpture.

Walk along the medieval fortifications that have been protecting Tallinn since the 14th century.

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

A turn of the century building boasting some of the most beautiful art nouveau architecture in Prague.

A surreal statue honoring Prague's favorite literary son.

Monument to a suicide protesting the Soviet invasion.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Macabre astrological automaton clock dating to the late 1400s.

If it hadn't been caught in time, a flaw in the design of this Manhattan skyscraper could have led to its collapse.

This strange portrait of six ladies with chicken bodies commemorates a count's dirty habits.

A stunning architectural yet functional feat, towering over Oslo.

The world's first invisible city square is an homage to a man who pushed the boundaries of art.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

A statue that would be at home in Rome can instead be found in the heart of Norway's oldest city.

This controversial monument was designed to lionize the Red Army, but also disheartened the Latvian people.

In downtown Oslo, a menacing and terrifying relief clings to a church wall.

Sweden's southernmost point is located in this charming fishing village.

This seventh-century fortification marked the western border of the Lombard duchy of Spoleto.