An abandoned Byzantine fortress and notorious prison.

A line of disused military bunkers built to defend against Nazi invasion lies hidden on the outskirts of the city.

This spaceship sculpture in the middle of the Slovakian capital looks like it just crash-landed.

The largest fountain in Bratislava.

A massive sculpture of an obscure Celtic coin that has become a symbol in Slovakia.

A once-fairy tale mansion now stands in a state of disrepair.

The inverted pyramid design of this station stands out amid Bratislava's urban landscape.

A unique hotel for the artistic soul.

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

At first glance, this area seems like just another city park, but the lush landscape hides a dark past.

Joe Cocker's 1988 concert at this site in East Germany marked a changing sea tide that would eventually lead to reunification.

Every half hour the eye-rolling clock face sticks out its tongue to mock the good citizens of Koblenz.

This fountain of a little boy that spits on passersby at erratic intervals is a town icon.

This almost a century old piece of architecture had been overlooked by most, except for the drunk and the homeless

A cheeky reminder about the value of art dangles above one of Olomouc's busiest streets.

Tiny communists hammer away on the Olomouc Astronomical Clock.

An ornate plague column – built to celebrate life – claimed the lives of numerous artisans during its construction.

Once home to artillery, this garden offers more peace today than it did during its war-torn past.

Plaques celebrating Lithuanian writers freckle a wall of this picture-perfect path.

The architect of this fanciful complex called it an "oasis for humanity and nature in a sea of rational houses."

Macabre astrological automaton clock dating to the late 1400s.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

Tall columns of volcanic basalt make up this improbable-seeming rock formation.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.