This unusual hostel provides a glimpse of life in a city under siege.

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

A bridge destroyed three times: once as a ruse, then in an actual attack, and finally for the movies.

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

This historic cemetery was inaccessible for several years due to dozens of land mines.

The haunting ruins of a military fortress turned astronomical observatory sit on a Sarajevo mountaintop.

This museum preserves the hand-dug tunnel that kept Sarajevo afloat during the Serbian siege.

A war-torn Olympic relic is being overtaken by graffiti and nature.

These warring psychedelic crags commemorate an unsuccessful military operation.

There's a mini version of Iguazu Falls hidden in the Balkans, and it's got a rope swing.

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

The only gulag ever to exist in socialist Yugoslavia.

Now abandoned, the world's first torpedo factory is crumbling into the sea.

Formerly Yugoslavia's "forbidden island," this sleepy little city still holds the abandoned remains of military strongholds.

The now-overgrown beach resort was once frequented by Yugoslav military elite.

This former estate of a fascist leader is now a burnt out ruin leading to a system of secret tunnels.

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

Once a state-of-the-art tuberculosis treatment spa, these ruins are now ruled by paintball players.

Yugoslavia's biggest underground airport lies in ruins.

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

This disused VLF radio station is no longer in service but the surrounding town still bears its name.

The ruins of a medieval castle that once belonged to one of the most powerful families in the Netherlands.

Its town washed away centuries ago, this lonely tower by the sea tells the tale of a mermaid and a curse.

A UFO-shaped event building originally intended to be a science museum showcasing the future.