The bizarre rocks of Đavolja Varoš are the result of natural erosion.

This spaceship-like Serbian monument reaches for the stars in celebration of the fallen fighters of fascism.

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

On top of a resort town as old as the Bronze Age sits an incredible war memorial statue overlooking the beaches below.

An ethereal glowing blue ocean cave in Croatia.

An abandoned brutalist monument whose history has been lost to the ages.

This brutalist monument is inscribed with 9921 names of Yugoslav partisans who perished during WWII.

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

One of the world's oldest olive trees, thought to be over 2,000 years old.

A wonderfully strange collection of 500+ stuffed frogs doing people things.

A sinuous path among steep cliffs creates a stunning sight in southwestern Serbia.

A beautiful mountaintop mausoleum devoted to a Montenegrin icon can't seem to make everyone happy.

Former military fort and site of untold horrors during WWII, this island may become the Adriatic's next luxury resort.

When Croatia became independent of Yugoslavia, the splintering governments left behind these concrete tunnels.

A tiny church on a man-made island in the Adriatic.

A curious cave church carved into the face of a cliff.

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

This Croatian island is for sale but no one is buying due to the dozens of accused Nazi sympathizers who were massacred there after WWII.

Longest fortress system anywhere in Europe.

For over 40 years, this quaint little house has teetered on a rock in the middle of a river.

This abandoned airplane hanger is said to have once been a top secret launch facility.

A wellspring of natural Viagra found in Bosnia.

This top-secret nuclear bunker hidden in a Bosnian mountain has been converted to a modern art exhibition space.

This abandoned Olympic skiing facility still bears the scars of the Siege of Sarajevo.