The underground airport Zeljava, codenamed “Object 505”, situated on the border between Bosnia and Herzegovina (BiH) and Croatia, near Bihac on one side and Plitvice Lakes on the other, continues to spark interest.
This military giant, with tunnels stretching 3.500 meters long, 20 meters wide, and eight meters high, is the largest underground airport in the Balkans. Construction began in 1955, and by 1968, Dragoslav Sobotka’s creation was ready for use by Yugoslavia.
Billions of dollars were allocated for the most expensive Yugoslav project, designed to house 120 aircraft, crews, a full arsenal of weapons, and massive reserves of fuel, food, medicine, and everything necessary in the event of a catastrophe. Equipped with its own sources of electricity and water, the military could survive a month in isolation from the outside world. The military fortress was designed to withstand a nuclear bomb.
Zeljava was also used during the war in Croatia, after which it became a pile of concrete surrounded by minefields. At the start of the BiH War, the Yugoslav People’s Army (JNA) decided to destroy the underground complex and, in 1992, planted 56 tons of explosives. The city of Bihac shook as a thunderous explosion from deep within the Pljesivica mountain marked a cataclysmic scene of fire and smoke on the horizon.
Interest in Zeljava persists today, fueled by the tunnels, which are at risk of collapse and are filled with toxic and radioactive substances.
A few years ago, Slovenian director Ziga Virc’s documentary “Houston, We Have a Problem” reignited the mysteries surrounding Zeljava and one of the Cold War’s and Yugoslavia’s greatest conspiracy theories.
The documentary explores the claim that Tito sold the Yugoslav space program to the Americans, secretly developed it in the underground facilities of Zeljava, and that the first human to land on the Moon was part of this program. According to this theory, Zeljava would have been the largest hidden space center in Europe.
NASA firmly denied this story, emphasizing how absurd it is to believe that then-President John F. Kennedy purchased anything from Yugoslavia, let alone a space program.
Despite the dangers of mines, toxic gases, and police, Zeljava continues to attract adventurers who drive on the runways and explore the tunnels. Some suggest that the airport could be transformed into a venue for concerts or other events in the future.
