Inside the plane-silhouetted entrances lie three and a half kilometres of underground tunnels – built to hide, service, and restock two fighter squadrons of the former Socialist Federal Republic of Yugoslavia (SFRY).

Blown up during retreat by the Military of Serbian Krajina in 1992, the explosion of 56 tons of explosives was reportedly felt from 20 kilometres away in the town Bihać. It is reported that the underground base burnt for 6 months. This destructive power can be seen first hand in the ripped apart meter thick bunker doors, leaving frayed steel rods in a jagged mess.

Today the tunnels are little more than a concrete shell – left dark and dusty. Four entrances make entry and exit easy, although the curve and corners of the tunnels pathways are deceptive, until you see light, you often don’t know if your going deeper into the mountain or on your way out.

A car can fit through entrance number 2, but if, while driving around inside, you spot another pair of headlights in the dark and you find yourself staring down the barrel of a rifle, answering police questions asked in broken English, you'll wish you had stuck to walking.

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