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

This truly palatial work of Communist-era architecture now sits crumbling on a Croatian beach.

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

Yugoslavia's biggest underground airport lies in ruins.

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

Dramatic sea stacks adorn the coast of this small village on the Adriatic coast.

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

An ethereal glowing blue ocean cave in Croatia.

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

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

A naturally beautiful, seemingly bottomless deep blue spring.

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

This ominous Albanian fortress houses tanks and downed planes as a reminder of their victories over Western imperialism.

This massive underground salt mine now holds a sci-fi theme park in its depths.

The remains of the last Bosnian fortress to fall to the Ottomans are still standing.

This cluster of little wooden huts once ground local farmers’ wheat into flour during the days of the Austro-Hungarian Empire.

These ruins in Volvi were once at the intersection of the Eastern and Western Worlds.

A tribute to an iconic act of defiance from the Croatian War of Independence involving a small car.

An architectural marvel that spans the Arda River, and has stories of a haunted past.

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

An abandoned monument remembering the "Pančevo Holocaust" now stands as a shadow of its former self.

The elliptical citadel resisted the advance of the mighty Ottomans several times, thanks to the military prowess of the "Dragon of Albania."

A grand Yugoslav memorial to the group of partisans who fought and died resisting western Serbia’s Nazi occupation.

UNESCO-protected ancient burial ground.