In the decade between 1991 and 2001, the Yugoslav state had undergone several ethnic wars resulting in the breaking up of the state. During that time, an underground air base known as Željava Air Base was used for aerial support. The air base was constructed for almost $6 billion and was considered the most expensive project in Europe only to be destroyed deliberately to prevent the enemy from using it. It has tunnels large enough to house squadrons of aircraft along with personnel and supplies for over a month. Now it is the largest abandoned military air base in Europe and here is more information about it.

Located on the border between Croatia and Bosnia-Herzegovina, under Plješevica Mountain, the Željava Air Base was the largest underground military airbase in the former Yugoslavia, and also one of the largest in Europe.

One of the entrances to the base.

Construction of the airbase, also known as Bihać Air Base and code-named Objekat 505, began in 1948 and finished in 1968. It cost approximately a whopping $6 billion, three times the annual military budgets of Serbia and Croatia combined, and was one of the most expensive construction projects in Europe.

The function of the airbase was to facilitate a nationwide early warning radar network in the Socialist Federal Republic of Yugoslavia (SFRY). Its radar on Mount Pljesevica, located at the center of an advanced air defense network, covered the airspace and territory of Yugoslavia and more.

It had five runways, numerous short-range mobile tracking and targeting radars, missile sites, mobile missile interceptor systems, motorized infantry bases, two fighter jets always on alert, military police stations and even a hunting lodge for civilian or military leaders to use during leisure. Though the access points were heavily guarded with orders to kill any trespasser, in practice, they were just turned away.

More abandoned aircrafts at Željava Airbase…

The cockpits of abandoned and rusting aircrafts at the base.

The base is so secure that it could withstand a direct hit from a twenty kiloton nuclear bomb, similar to the one dropped on Nagasaki.

The airbase has underground tunnels which housed two fighter aviation squadrons equipped with MiG-21bis fighter aircraft, one reconnaissance squadron with MiG-21R aircraft and all the maintenance facilities required for them.

The tunnels are a total of 3.5 kilometers long with four entrances protected by 100-ton pressurized doors. They were lined with semicircular concrete shields to cushion the impact of any bombs.

The facility is also equipped with water supply, power generators, crew quarters and strategic military facilities. There was also a mess hall that can feed 1,000 people at once along with enough food, fuel (supplied by a twenty-kilometer underground pipe network) and weapons to last thirty days.

The airbase was used extensively in 1991 during the Yugoslavian wars. The runways were later destroyed by the Yugoslavian People’s Army, and the facility was completely destroyed by the Military of Serbian Krajina in 1992 to prevent opposing forces from using it.

The Yugoslavian People’s Army during its withdrawal placed explosives in pre-built spaces which were explicitly designed for the purpose of destroying the runways. The Military of Serbian Krajina used fifty-six tons of explosives to destroy the facility. The explosion was so powerful that it shook Bihać, a nearby city, and according to the villagers, the smoke rose from the site for six months. It also caused considerable damage to the surrounding environment.

The facility is heavily mined and is now being used as a training facility for dogs to detect mines. It also serves as a waypoint for migrants.

There were several attempts at reconstructing the facility but all were canceled due to financial limitations. An asylum for migrants was scheduled to open in 2004 or 2005, but the idea was eventually dropped. It was also to be developed to become a part of the Slunj Military Training Grounds and the barracks at the Udbina Complex, but these plans were also abandoned because of an agreement forbidding any military facility closer than fifteen kilometers on the border between Croatia and Bosnia-Herzegovina.

Here are more pictures from the site.

A destroyed smuggling truck

 The inside of a rusting aircraft

The destroyed tunnels

One of the runways

An abandoned and rusting aircraft

[source: Wikipedia]