Underground Air Base Zeljava

Once known as one the largest underground military air bases in Europe, Zeljava is today a key part of the GWT2P cross-border tourist destination with two national parks - Plitvice Lakes and Una!

Licka Pljesivica

Zeljava is woven into the magnificent mountain range Licka Pljecivica, the second longest mountain in the Republic of Croatia which stretches from the Plitvice Lakes National Park to the River Zrmanja in the south of Croatia. With its natural extensions, the Medvjedak hill in the north and the Kremen and Postak hills in the south, Licka Pljesivica is over 100 km long and abounds in biologically diverse natural heritage systems with many stunning landscapes and one of the most impressive lookouts in Croatia - the one from the Gola Pljesivica Peak, the highest peak of the northern part of the Licka Pljesivica mountain.

Built just under the Gola Pljesivica peak, Zeljava (Željava) underground air base is now positioned in the center of the GreenWay Tour 2Parks destination, on the border between the two neighboring local communities, now as trusted partners committed to developing friendly and mutually beneficial relations.

The important underground part of the Base, as well as the runway 4, and parts of the runways 1 and 3 belong to the Republic of Croatia, administratively the Municipality of Plitvice Lakes, while the runways 2 and 5 belong to Bosnia and Herzegovina, administratively the Town of Bihac.

Together with two national parks, both local communities are now the main partners and signatories to the GWT2P Cross-Border Partnership and Cooperation Agreement.

From the Initiative to the Realization of the Vision

At the beginning of our work on joint development agreement, the lead partner, the Municipality of Plitvice Lakes, accepted the GWT2P initiative and expressed interest in taking over the abandoned military airbase and bring about many new development opportunities through joint GWT2P development project. In August 2014, the Municipality had approached the Ministry of State Property (formerly the State Office for the Management of State property) Advisory Program, which lasted from August 1 to September 15, 2014.

After years of calm anticipation, during which we sensitized the public on the GWT2P project and planned activities, the best possible thing happened for all local residents in the region. In 2019, Zeljava Airbase was assigned to the Municipality of Plitvice Lakes and the same happened across the border where the rest of the base was assigned to our partner, the Town of Bihac.

Residents of the surrounding local communities have sacrificed a great deal for this base: during construction, two Croatian villages of Veliki and Mali Baljevac were completely emptied and razed to the ground, and during the last war, Zeljava was a the zone from which the besieged town of Bihac and the surrounding local communities in both countries were mercilessly attacked. Therefore our vision is that the people and the local communities that gravitate toward Zeljava receive the greatest benefit from this valuable and once the most expensive man-made object.

In the 21st Century, Zeljava is preparing to provide a significant contribution to both sustainable and socially responsible development that take equal care of economic, social, and environmental factors while ensuring citizens' welfare, and prosperity of current and future generations of our region.

Now, there's a big challenge ahead for us all; this is an opportunity for the millennium step forward towards a new paradigm that completely transcends artificial political boundaries, different values, worldviews, and ideologies. This capital man-made object can become a powerful engine of local and regional development and respond to the challenges imposed by the modern day life and environmental degradation; fully committed to the common good and well-being of all - through joint efforts and work involving local stakeholders at all levels.

Zeljava is inseparable from the magnificent Licka Pljecivica Mountain, a true natural gem of our destination highly worthy of our shared attention! Find more about it under Explore Local!!

Activity Suggestions

Although not yet open to the public for security reasons, the airbase's surrounding area has some fun and interesting activities to offer - fine dining restaurants, hotels, traditional handicrafts, as well as great local guides who will gladly take you on a biking or a walking tour around the airbase. Since the offer is constantly changing and growing, the best thing you can do is to browse through our newest and updated information on all activities, as well as contacts of guides and organizers that can be found under Events and Activities / Monthly Experience Ideas. Local people are very friendly and interconnected, and will gladly refer you to more interesting activities in the area.

Essential Safety Tips

It is important to remember that this area was part of intense military operations. A great ecological damage was done with the destruction of the base and there is still a great risk of polychlorinated biphenyls, chemicals and radioactive americium-241 from hundreds of ionization smoke detectors. For the time being, the area of the underground base is not open for visits, therefore CAUTION:

• do not enter the area of the former military base on your own initiative;
• take care of your own safety and that of others who may be affected by your decisions /actions;
• stick to established trails, don't take shortcuts through the deserted area or private properties;
• ask for and follow the advice given by your hosts or local guides;
• take responsibility for your potential curiosity in exploring a “hazardous area”.

By using local tourist services, you provide great support to local artisans, entrepreneurs and "guardians" of traditional heritage and thus to the social and economic revitalization of local villages!

Zeljava in Brief

The expansion in the construction of numerous well-hidden military bases around the world took place during The Cold War between the United States of America and the Soviet Union, which was characterized by a relentless arms race on both sides and on a global scale, including the nuclear arms race. Of course, the locations of those bases, and above all their technical characteristics, were secret, and that period was also the time when the Zeljava underground air base was built, which had a strategic significance in ensuring the neutrality and independence of the then Yugoslavia from both the Western and Eastern blocs of the Cold War. With the fall of communism in Eastern Europe in 1990 and the unification of Germany, the Cold War ended and a large number of military bases lost their primary function and were being either dismantled or left to decay. In our case, sadly, that final period was marked by the terrible and unjustified Srbia's military aggression against Croatia and Bosnia and Herzegovina.

In 2020, probably the most lavish book was published about Zeljava when it comes to the publication of previously undisclosed, secret, and exclusive archival materials. The book was written by Serbian authors Bojan Dimitrijevic and Milan Micevski who gained access to numerous archives of the former Yugoslavia located in Serbia: Tito's Underground Air Base: Bihać (Željava) Underground Yugoslav Air Force Base, 1964-1992“, published by Helion Limited.

Dragoslav Sobotka

But when it comes to the man who designed it, then a particularly interesting source of information is the exclusive interview which chief designer and engineer Sobotka gave to Professor Radmila Tonkovic in 2010. Radmila Tonkovic spent 24 years in the Air Force and Air Defense Command of Yugoslavia and later Serbia. She was also a pilot, and later for a period of 18 years, an editor in the aviation magazine Aeromagazin, in which she published probably the last interview with the engineer Dragoslav Sobotka, who was the chief designer of the construction part and the leading designer of the underground facilities at the Željava airport. It was then that she wrote that Sobotka was "the most meritorious and competent" source to answer question, “How the Object was created?” (Tonkovic, 2010).

In the interview with Mrs Tonkovic, Sobotka said that the initiator of the construction was the then Yugoslav Air Force, and that initial preparations started in 1955 when Sobotka and his superiors visited and studied an underground military facility in Sweden. Already a year later, a commission was formed that devoted itself to the creation of the project program and documentation, but for only one object of the future underground military base, and the engineer Sobotka was appointed as the chief designer in the "Bureau for Special Design of the Construction Administration of the Yugoslav National Army" (Tonkovic, 2010).

The designers' task was to produce a construction drawing for the first facility that was supposed to provide accommodation for two to three reinforced squadrons of fighter aircraft (then the most modern MiG-21 aircraft) with accompanying rooms for: "the command, pilots, aviation technical service and resources, ammunition, fuel, technical and drinking water, sanitary facilities and a reserve source of energy" (Tonkovic, 2010).

However, already during the design phase, a new request came from the top-level of the then Yugoslav Air Force for the expansion of the base, namely, it was requested that within the framework of the first facility, an additional three must be built that will serve for:

• accommodation of a larger number of planes: one "fighter aviation regiment with 3 to 5 squadrons";
• accommodation of "larger number of staff and greater comfort" compared to the first project;
• and the placement of "devices and services necessary to ensure the life, work and combat activities of the regiment in the conditions of classical and nuclear war - which are intended to serve as a possible outlet for air traffic control with a meteorological station (everything connected by an elevator and a shaft with the interior of the building) (Tonkovic, 2010).

Geostrategic position

The geostrategic position of the underground military base was chosen after detailed research. As with all military facilities the main requirement was to be placed on the geostrategic base: deep enough in the national territory and at the same time equally distant from all important facilities and strategic objectives.

The morphological image and the position of the impressive Licka Pljesivica Mountain, with numerous valleys and ridges, fully met those requirements. The terrain was an ideal natural barrier against surprise attacks and position of the mountain provided an opportunity for a tactical surprise because the planes could take off safely and unnoticed from the radar shadow of the mountain.

Due to the limestone structure of our mountain, the intervention of speleologists was also required to determine the presence of underground caves. They found that caves extend along the entire length of the gallery (width and height up to 20 meters at the very bottom of the opening!), so they were later bridged and fortified with reinforced concrete structures (Tonkovic, 2010).

A large number of contractors took part in the works in the utmost secrecy, and the Croatian villages of Veliki and Mali Baljevac were evicted and demolished - only the Baljevac cemetery was left untouched, it is still there today between entrances 3 and 4 to the underground base.

The exterior of the base had five runways, two ascending-descending and three ascending runways. Barracks were located in the village of Licko Petrovo Selo that also served as the logistic base. Almost all members of the base lived with their families in the Town of Bihac where the whole quarter of the town, called Harmani, was built for the airport. Željava air base was also one of the two airports in the former Yugoslavia with the 24-hour operation, and home to the renowned 117th-Hunting Aviation Regiment that was composed of only the best-trained pilots (Tonkovic, 2010).

Impressive technical characteristics of the base:

• three galleries to accommodate 58 aircrafts were linked together in the shape of the letter M. The middle gallery was extended with vertical supports / columns 15.40 m wide and about 10 m high, and it also had an additional gallery that was used for inspection and work on up to two airplanes;
• all three main galleries are arched: lengths 350, 400 and 500 meters, width at the base about 20 meters and height 8 meters;
• at the intersections of galleries, the height of the vault reaches 12 meters;
• the total length of the underground tunnels (galleries and auxiliary rooms) was 3500 meters;
• the profile of the gallery and the entrances are built to match the dimensions of the MiG 21;
• 4 entrances and exits, the middle one of the original building was also used as an entrance for personnel and airplanes (in case of a nuclear attack, degassing chambers / decontamination chambers were also built), and the other three entrances were used for airplanes;
• all entrances were connected to the two main runways by taxiways, and their distance was designed in such a way as to prevent the simultaneous destruction of two entrances-exits;
• the planes were deployed inside the facility with the help of electric vehicles;
• all aircraft parking spaces had a jet fuel dispenser (Tonkovic, 2010).

As the period of the Cold War was marked by insane nuclear armament, Zeljava was also equipped in a way to provide people with safe shelter and autonomous use of the base for up to 30 days:

• own source of electricity and water; power, water and wastewater network;
• two backup diesel-electric power plant of 1,000 kVA and 625 kVA;
• 13 air-conditioning chambers with specially protected ventilation shafts (also spare exits to the surface);
• manholes for polluted air and aggregate exhaust valves; used also for refueling;
• fire protection system;
• kitchen and dining block;
• outpatient clinic;
• bedrooms;
• warehouses of lethal means and spare parts;
• station for recharging aircraft and ground batteries;
• signal devices and loudspeakers connected in 10 sound circuits for monitoring and control of movement in and around the base;
• interior rooms separated by 56 heavy, steel, bullet resistant doors;
• heavy reinforced concrete doors at the entrances to the galleries were opened manually and electrically, they were 1 m thick, 9 m wide, 21 m high and weighed more than 100 tons and were placed in separate niches on the side of the galleries with built-in anti-shock safety valves;
• the base had its own storage for diesel and aviation fuel with a distribution installation in the galleries, and it was supplied with kerosene through its own, more than ten kilometers long and completely combat-secured pipeline from the military warehouse on the hill Pokoj near Bihac;
• it had a decontamination room, and was resistant to a potential direct 20 kilotons nuclear attack (Tonkovic, 2010).

Ideal temperatures and air humidity were ensured in the underground rooms, and in the aircraft galleries and in some warehouses the temperature was "reduced to 18°C for practical and economic reasons".

During the construction of the Base, the so-called "aqua-system" was used for the first time. It was used for the storage of jet fuel, which played an important role in securing the Base in case of "attacks, explosions or fires“. The aqua-system had a "water cushion in 5 cylindrical steel tanks, each with a capacity of 100 tons. A special steel dome was also located on the observation hatch in the air traffic control room, which protected against direct hits from machine gun bullets and close hits from rockets and bombs (Tonkovic, 2010)."

The World we Live in!!

Zeljava, then one of the largest and the most modern military air bases in Europe was built with the money of all nations of the former Yugoslavia. The exact amount of that money will never be known, but researchers estimate that the total amount of money spent by Yugoslav taxpayers on this base alone fluctuated between 5 and 8 billion US dollars, and this was not the only such investment. At the end of the 70s, another secret underground facility was built in the wider area of Sarajevo at a depth of 280 meters and equipped with "a fresh water tank, powerful generators, a ventilation system, conference rooms and private quarters for the former president and his 350 closest associates - and all this costed the citizens of former Yugoslavia 4.6 billion US dollars (Tonkovic, 2010)!

American General Douglas MacArthur spoke very clearly about the Cold War, saying: “Our government has kept us in a perpetual state of fear - kept us in a continuous stampede of patriotic fervor - with the cry of grave national emergency. Always there has been some terrible evil at home or some monstrous foreign power that was going to gobble us up if we did not blindly rally behind it by furnishing the exorbitant funds demanded. Yet, in retrospect, these disasters seem never to have happened, seem never to have been quite real (Higgs,1994)".

During Cold War period, between 1960 and 1990 alone, massive military spending reached 21 trillion US dollars globally (Schulz, 2008)!! The main arms exporters then became the United States and the Soviet Union. "Given that these two States were the major players during the Cold War, both were exporting arms to their respective allies in several proxy conflicts, from Vietnam to Afghanistan (UNODC, 2019)!!!

In 2022 alone, 2.24 trillion US dollars was spent globally on military equipment!! Three-quarters of the global arms market today is occupied by the US, Russia, France, China and Germany, and these five countries earn an estimated $85 billion a year from the sale of their weapons. At the same time, 9,000 people die every day of hunger - one of the direct consequences of the wars that these countries finance (Oxfam International, 2023)!!!

Let's think, critically!

End of Initial Purpose

Zaljava was 24 years in its original military function, primarily to defend all the nations of the former federal state, but unlike other Cold War bases, its end was marked by the use of force for real military purposes.

Unfortunately, as if there weren't already too many brutal and destructive invasions and wars in our region, a terrible Serbian aggression broke out at the moment of the inevitable disintegration of the former Federal State, during which the Zeljava base was used in attacks on the very same people it was supposed to protect. Combat air crafts were ascending from the airbase on the warpath against the people who built it, attacking citizens and critical infrastructure in both Croatia and Bosnia and Herzegovina, including Bihac which had been under agonizing siege for years, ruthlessly attacked and faced with the great danger of experiencing a horrible tragedy, like the one in Srebrenica.

On 16 May, 1992, when it became clear that the paramilitary forces occupying the base will not be able to continue unhindered with the military operations, they began wide scale destruction of the base with estimated 50 tons of explosives (Tonkovic, 2010). Although placed fully out of service by massive explosions and destruction of key buildings and runways, the airport was still in occupied territory until the liberation in the operation "Storm" in 1995.

There is nothing more important to our future than a lasting peace, not only in this region but around the world. Only under such conditions we have the opportunity to take the much-needed steps to shift our world onto a sustainable and resilient path - and start working for the people, our planet and prosperity for all!!

Zeljava in the 21st Century

Certainly, in the 21st century, this impressive complex has a great opportunity for a completely new role and purpose. In 2019, the lead GWT2P partner, the Municipality of Plitvice Lakes, has has been awarded a state tender and has a golden opportunity to turn the base into a powerful engine for regional’s long-term sustained economic growth that will lead to greater prosperity, well-being, and quality of life of its citizens. A historic opportunity to demonstrate conscious responsibility for the impact we have on our society and the environment, for transparency in the decisions we make and the activities we undertake that have a direct effects on our society and our environment, for ethical behavior that includes honesty, fairness, respect and integrity in every interaction with our internal and external stakeholders.

GWT2P Vision

Self-sustaining development of the base that is now a key part of the large regional tourist destination with 2Parks as the leading attractions, can become a reality even during its present dehumanized phase through well-prepared, socioeconomically patient and collaborative work.

With its potential, and guided by the principles of social responsibility and the new economic paradigm that require the application of new system structures, new ways of thinking and new consciousness, Zeljava can easily give a strong impetus to sustainable and socially responsible development that gives equal attention to environmental, social, and economic concerns and goals, to development that cares for all members of local communities, uses natural resources responsibly, and thus meets the rights of our future generations.

All mentioned above, requires the development of a new form of coordination between stakeholders in the public, private and civil sectors concerning the management of common goods, because such capital projects can attract the attention of the kind of investors that do not meet the required ethical standards. Therefore, an essential prerequisite for success was the gathering of all key stakeholders in local communities in the surrounding area of the Base for which we have created the conditions through our joint GWT2P project and the creation of our joint eco-adventure tourist destination led by two national parks. With this foundation, the Zeljava Base itself will become a unique hub for the development of socially responsible entrepreneurship and public-private partnerships - a unique hub that promotes science and culture, supports and preserves tradition, cultural, natural and historical heritage and authentic and autochthonous customs and products of our local communities and the region as a whole.

Realization of the vision will be a great challenge and test, just like everything else that is transformative - it is now solely up to us to boldly step outside the outdated paradigms and divisions and put our full focus on building a new system of values and ethics that respects and supports local responsible, creative, and innovative entrepreneurs and citizens who are our key associates in the development of Base as a future dynamic business, cultural, scientific, entrepreneurial and sports zone for numerous domestic and foreign guests.

The active involvement of the local population and their proactive engagement in creating the future of the Base should be of primary importance for us, especially the recognition and appropriate evaluation of the potential of all those contribution motivated local entrepreneurs, craftsmen and artists, as well as all those contribution motivated members of our communities who had to emigrate, and today wish to contribute to the development of their homeland.

Built in the 20th century for the purpose of war, now in 21st century Zeljava has a chance to get a meaningful role in peace - for the benefit of all people in surrounding local communities!

Explore Local represents a part of our natural and cultural heritage; for a fuller overview of the tangible and intangible heritage, see our Interactive Map under Experiences and Events and Activities Calendar with many suggestions for your itinerary.

References

1. Higgs, R. (1994, July 1). The Cold War Economy. Independent institute. ˂https://www.independent.org/publications/article.asp?id=1297>
2. Oxfam International. (2023, May 22). Top five arms exporters hit yearly sales of $85 billion as 9,000 people die from conflict-driven hunger every day.Global military spending reached $2.2 trillion last year, enough to cover the UN appeal more than 42 times.  Oxfam International. ˂https://www.oxfam.org/en/press-releases/top-five-arms-exporters-hit-yearly-sales-85-billion-9000-people-die-conflict-driven#:~:text=The%20top%20five%2Darms%20exporters,billion%20worth%20of%20arms%20yearly.>
3. Schulz, B. H. (2008). Cold War. U Kurtz, L. (gl. ur.) Encyclopedia of Violence, Peace, & Conflict (Second Edition) (pp. 310 - 319). ˂https://books.google.hr/books?id=EBzxsURb4-cC&lpg=PP1&pg=PP1#v=onepage&q&f=false>
4. Tonković, R. (2010, November 27). Podzemni vojni aerodrom Željava kod Bihaća - jedan od mitova SFRJ. Aero magazin. ˂https://www.gradjevinarstvo.rs/tekstovi/1454/820/podzemni-vojni-aerodrom-zeljava-kod-bihaca-jedan-od-mitova-sfrj>
5. UNODC. (2019). The history of the legitimate arms market. UNODC. ˂https://www.unodc.org/e4j/zh/firearms/module-3/key-issues/history-of-legitimate-arms-market.html>