Like something out of a Bond film, the giant Zeljava airbase was carved into a mountain between Bosnia and Croatia and designed to withstand a nuclear strike.
But for decades it sat idle, with only the occasional intrepid tourist daring to venture into its crumbling cavernous core.
Built in secret in the 1960s to hide a fleet of Soviet fighter jets in what was then Yugoslavia – a socialist federation that sought a middle ground between Moscow and Washington during the Cold War – it had its own power, water purification and ventilation systems and could…
