Constructed between 1957 and 1968 at an estimated cost equivalent to several billion USD, Zeljava Airbase was designed to be one of Europe's largest subterranean military complexes. Built inside the limestone core of Plješevica Mountain, the facility contained over 3.5 kilometers of reinforced tunnels designed to shield two full fighter squadrons, command centers, and personnel from direct nuclear strikes.
Blast Door Engineering & Tunnel Layout
The facility featured four primary outer tunnel entrances fitted with 100-ton hydraulic concrete blast doors designed to mitigate explosive shockwaves. Inside, self-contained water filtration units, power generators, fuel reserves, and air scrubber systems allowed the complex to function fully sealed off from the outside environment for extended operational periods.
| Engineering Parameter | Archival Specification |
|---|---|
| Total Tunnel Length | 3.5 Kilometers (Reinforced Vault Arc) |
| Blast Protection Rating | 20 Kiloton Nuclear Direct Impact Equivalent |
| Runway Outlets | 5 External Concrete Runways integrated with mountain base |
| Current Site Status | Severely scorched interior, unexploded ordnance hazards in surrounding buffer zones |