History & Abandoned Places

Željava Air Base

Objekat 505 — the underground fighter base of socialist Yugoslavia, straddling the Croatian–Bosnian border under Mount Plješevica.

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COUNTRY: Croatia
REGION: Lika & Plitvice
BEST TIME TO VISIT: April–October in dry weather
DURATION: Half a day

ABOUT THE DESTINATION

Željava is the ghost of socialist Yugoslavia’s air power: a vast underground air base carved into Mount Plješevica on the border between Croatia and Bosnia, near Bihać. Code-named Objekat 505, it was built in secrecy between 1948 and 1968 and became the largest underground military air base in Yugoslavia and one of the largest in Europe — a complex of tunnels long enough to shelter an entire fighter wing, with hangars cut into the rock, a full-length runway above ground and radars on the mountain above. SFRY spent around 6 billion (current) dollars on it — one of the most expensive military construction projects in Europe. Destroyed by explosive demolition in 1991–1992 during the breakup of Yugoslavia, it is now one of the most atmospheric abandoned places in the Balkans: cratered runways you can walk, tunnel mouths opening into the dark mountain, a derelict Dakota aircraft standing guard, and unrivalled views over the Krajina from the radar plateau above. It is a magnet for motorcyclists — the roads around Plješevica and the Una valley are among the best rides between Lika and Bosanska Krajina — and for photographers and urbex travellers, and visiting it pairs naturally with Plitvice, Rastoke and Bihać.

MAP & LOCATION

Željava Air Base

THROUGH THE LENS

From the road

HISTORY IN PICTURES

History in pictures

Historical photographs of this place through its darkest and most defining years — shown for education and remembrance.

F-84G and RF-84G jets of the Yugoslav Air Force dumped at the entrance to Željava air base — The Thunderjets at the gate — F-84G and RF-84G Thunderjets of the 117th Fighter Aviation Regiment still stand dumped at the tunnel entrance, where they were parked when the base was abandoned in 1991. They were already veterans then: the Republic F-84 Thunderjet was the first jet to enter JNA service in the 1950s, bought from the United States before Yugoslavia’s split between the blocs.

The tail of an RF-84G reconnaissance jet with the faded Yugoslav star at Željava air base — The five-pointed star — the tail of an RF-84G reconnaissance Thunderjet. Željava hosted not only fighters but a photo-reconnaissance squadron: jets that mapped the borderlands of the non-aligned federation from the Adriatic to the Greek border. The fading star on the tail marks the era when Yugoslavia’s air force flew both American and Soviet hardware.

The mortal remains of the F-84G Thunderjet serial 10531 at Željava air base — Serial 10531 — the mortal remains of an F-84G Thunderjet. Around 200 Thunderjets flew with the JNA from 1953; by the 1970s they were being replaced by MiG-21s, and the survivors ended their lives as gate guardians and training airframes at Željava, the base built to keep a superpower war away from Yugoslav skies.

The stripped cockpit of an F-84G Thunderjet at Željava air base, open to the sky — An empty cockpit under open sky — the stripped cockpit of an F-84G. Everything removable was taken in the 1990s: instruments, seats, radios. What remains is the shape of the machine that trained the first generations of Yugoslav jet pilots, and the quiet of a base that was abandoned, then destroyed, and never used in war.

The runway of Željava air base leading to the tunnel entrance in Mount Plješevica today — Today — the runway toward the mountain. The pre-built demolition chambers were fired in 1991 as the JNA withdrew, and 56 more tonnes of explosives finished the job in 1992; the blast shook Bihać and smoke rose from the tunnels for months. Thirty years on, the cratered runway and the tunnel mouths are free to walk — a Cold War megastructure left to the riders, photographers and climbers who find their way up Plješevica.

HISTORY & CULTURE

The Story Behind the Place

Željava was born of the Tito–Stalin split of 1948, when Yugoslavia — expelled from the Cominform and fearing Soviet invasion — began building a hardened air base able to survive a nuclear war. The site under Mount Plješevica was chosen for the mountain’s solid limestone and its position deep in the interior, and construction, code-named Objekat 505, ran in strict secrecy from 1948 to 1968, modelled on the Swedish Göta Wing mountain hangars. Around 6 billion of today’s dollars went into the complex — one of the most expensive military construction projects in postwar Europe — for a system of tunnel galleries cut more than a kilometre into the mountain, four tunnel exits onto the taxiways, underground fuel and ammunition stores, a full-length runway above ground and a radar station on the plateau above. From the 1970s the base hosted the 117th Fighter Aviation Regiment flying MiG-21s, alongside the veteran F-84 Thunderjets of earlier decades that remained standing at the gates. As Yugoslavia dissolved in 1991, the JNA withdrew and detonated the pre-built demolition chambers built into the runway for exactly this purpose; in 1992 the Army of Serbian Krajina completed the destruction with 56 additional tonnes of explosives — the blast shook Bihać, and locals reported smoke rising from the tunnels for six months. Since the war the complex has been administered jointly by Lika-Senj County and the city of Bihać, and repeated plans to turn it into a joint tourist attraction have never been realised — which has left it raw, unguarded and free to explore, one of the great Cold War relics of Europe.

TOP THINGS TO DO

Experiences Not to Miss

THINGS TO DO

Ride the Plješevica & Una Roads

Željava has become a cult motorcycle stop: the approach roads over Plješevica and along the Una are among the best rides between Lika and Bosanska Krajina.

TOP ATTRACTIONS

Sights & Highlights of Željava Air Base

ATTRACTIONS

Objekat 505 — the Underground Base

The underground complex itself: tunnel entrances cut into the mountain, hangar galleries, command spaces and the cratered runway above ground.

FOOD & DRINK

WHERE TO EAT

Grills and trout restaurants in nearby Bihać (across the border)

Village konobas on the Plitvice plateau road

HOTELS & STAYS

WHERE TO STAY

Camps and lodgings around Plitvice (20 minutes away) — see Camping in the Plitvice guide

Hotels and guesthouses in Bihać (Bosnia and Herzegovina side)

ITINERARIES

Keep Driving

More here soon — the road is still being mapped.

NATURE & WILDLIFE

The Living Landscape

Mount Plješevica above the base is forested highland karst on the edge of the Plješevica–Una corridor: beech and pine woods, open glades and the clean air of the frontier mountains. The abandoned site itself has been reclaimed by nature — grasses through the runway cracks, bats in the surviving tunnel sections, and birds of prey over the slopes. Wolves and bears move through the wider Plješevica forests, and the Una river valley nearby is one of the cleanest rivers in the Balkans, with its characteristic emerald water.

SEASONS

Best time to visit Željava Air Base

JanFebMarAprMayJunJulAugSepOctNovDec

Dry weather only — the tunnels are best avoided in rain; autumn mist adds atmosphere.

See what's in season in April

PLAN YOUR VISIT

Practical Information

Getting There

From the Croatian side, Željava is reached from the D1 between Udbina and the Plitvice plateau, following signs for the village of Željava (Općina Plitvička Jezera). From Bihać (Bosnia) the site is about 20 minutes up the mountain road. There is no public transport.