This abandoned Slovenian military barracks has become a punky-political art squat.

This one-time health resort was used by aristocrats around the world.

Trimmed trees grow alongside the graves like topiary tombstones.

A World War II evacuation tunnel turned into a history display of Croatian state and people.

This 135-year-old weather station studied the effects of the climate on human health.

Island wonderland for communist autocrats.

The big toe of this towering monument to a Croatian national hero is worn from years of superstitious rubbing.

This beautiful Croatian fortress is haunted by legends of forbidden love.

This abandoned Croatian stronghold never saw a great deal of conflict but it is still a beloved relic nonetheless.

This military tunnel dates back to World War II and provides visitors with a little wartime adrenaline.

Now harmless, this looming post struck fear into the heart of medieval troublemakers.

An ancient knight and a symbol of the city's freedom.

A tower marking the spot where Yugoslavia began its resistance against the invading Nazis stands neglected, but not quite forgotten.

Croatia's towering concrete blossom grows from the site of a World War II concentration camp.

One of the best-preserved Roman amphitheaters is still used today, but for less brutal events.

Humble beginnings for one of the world's most famous scientists.

This huge metal monument is slowly being stripped to its concrete skeleton.

Large, airy hallways hide within an impenetrable fortress that beckons urban explorers.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

Where the lovelorn find a home for their sentimental keepsakes.

A musical instrument played by the sea.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

Different sections of the Zemun Fortress were built in the 14th and 15th century as a response to the advance of the Ottoman Empire.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.