History and adventure tour

Zeljava airbase

Yugoslavia’s Hidden Base

Step inside a secret Cold War airbase and uncover the stories hidden beneath the mountain.

Client Satisfaction Rate

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Once Top Secret

Why Zeljava is unique?

Underground Scale

Over 3 km of massive tunnels carved into the mountain, once designed to protect military jets.

Cold War History

Built in secrecy, Zeljava was one of Yugoslavia’s most strategic airbases during the Cold War.

Secret Stories

Discover real-life tales of pilots, soldiers, and the hidden life inside this top-secret base.

Guided Exploration

Explore safely with an expert local guide who brings the airbase’s history and secrets to life.

Guided tours

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About the tour

Explore the Abandoned Airbase

Step inside 3 km of secret tunnels.

Uncover hidden stories, wander through secret tunnels, explore abandoned rooms, and capture unforgettable photo opportunities while experiencing the history and mystery of this Cold War airbase.

About the airbase

Zeljava Airbase: code name Objekt 505 or Klek

Picking neither side, Yugoslavia found itself between NATO and the Warsaw Pact. Building Zeljava Airbase was a strategic defense against any potential invasion.

Defence

Nuclear Protection

Engineered to survive a 20kt nuclear attack, the airbase could function continuously for 30 days without outside support.

Aircraft

Fighter & Reconnaissance Fleet

At its peak, Zeljava Airbase housed 58 fighter airplanes, including reconnaissance aircraft, ready for rapid Cold War deployment.

Cost

Monumental Project

At an estimated 6 billion dollars, Zeljava was the most expensive military project in Europe at the time.

Destruction

Final Days

During the outbreak of the Yugoslav war, the JNA destroyed the airbase to keep it from falling into opposing forces’ hands.

Group discounts (3+ people) apply at checkout.
Private tours on request
Minimum 2 adults
Cancel up to 24 hours in advance for a full refund
Languages: ENG, CRO
Difficulty level: Easy
Public group size: 2-6 (max 15)
Private group size: max 50 (shorter tour)

good to know

Essential Tips Before Your visit to Zeljava

Location & Directions

Zeljava is located on the Croatia–BiH border, but visits take place from the Croatian side. Keep in mind the border proximity so occasional police checks are possible.

Parking & Toilets

There’s plenty of parking at both the airplane and tunnel areas. Please note, there are no toilets on site.

Fee or Free

There’s no entrance fee to visit Zeljava. Keep in mind, mobile phones may switch to Bosnian(non EU) networks near the border.

Testimonial

What Our Guests Say

99% satisfied guests

Unmissable experience in Croatia

Antonio was an incredible guide and this is probably the best tour I’ve been on. He shared and incredible wealth of knowledge on the base and took us on an extensive tour of the entire facility. I learned a lot and would say you can’t miss this experience if you’re in the Balkans.

Daryl Merkel

TripAdvisor

Don't sleep on the BEST tour in Croatia!

This was the BEST tour we've done in Croatia, and it was definitely one of the more unique tours we've ever done. Yes you can explore the base/tunnels on your own, but Antonio is AMAZING and really humanizes the tour for you with information, stories, and personal accounts of time spent at the base. If you didnt have him, you really wouldn't know what you're looking at or the significance of it, and you'd probably get lost. Our tour was about two hours which was the perfect length.

Tori D

TripAdvisor

An excellent adventure!

I'd been aware of Zeljava from a few TV series and was excited to visit. Antonio was an great guide and brought the place to life explaining the political and structure complexities of the base. Highly recommended if you like exploring these types of places, my 9 year old really loved it also.

James

GetYourGuide

The guided tour was both fascinating and exciting

Our guide, Antonio, was extremely knowledgeable and passionate, sharing facts, stories, and local history that brought the base to life. Walking through the tunnels and standing by the abandoned aircraft ramps felt like stepping back in time. The atmosphere was both mysterious and captivating. A truly unique experience that I highly recommend to anyone interested in history or looking for something different to explore in northeastern Croatia.

Oscar

GetYourGuide

Highly recommended!!!

Antonio - our friendly, polite and pleasant guide - showed us around inside & outside of Zeljava. He lives in the city and has so much deep background knowledge about the history and function of several parts of the airbase. It was such a pleasure to walk with him through the corridors and listen to the storys about the working conditions, processes and equipment used there. 🙃 He caters about our wishes & questions and we had a nice talk. 💬 Before the tour starts he sent us helpful information about the tour and how to dress. 👍🏻

Tim

GetYourGuide

Highly recommended air base tour

A totally recommended experience. Our initial idea was exploring the base on our own, but we saw the tour and it was a success to get it. Antonio is a really good local guide who knows by memory the base and its history. He didn’t just show us what everyone sees there but a lot of hidden rooms like intelligence laboratories, pilots health-check rooms or powering facilities. He also told us real stories from ex-militaries that were there, and he was very friendly with our questions. If you like history, military aviation or just enjoying a nice tour you can not miss it.

Adrian Garcia

TripAdvisor

Into the Underground

Where History Meets Adventure

Walk through Zeljava Airbase and hear why this unique underground tour leaves a lasting impression on our guests.

Book Your Adventure

info@thrillquest.hr

+385 99 840 35 36

Frequently Asked Questions

any question ? we got you

Where is the Zeljava Airbase located?

The airbase sits on the border of Croatia and Bosnia & Herzegovina, near Plitvice Lakes. The tour takes place on the Croatian side.

Why take the tour instead of visiting on your own?

For safety, expert guidance, and in-depth history you won’t get on your own.

What should I bring?

Comfortable shoes and warm clothes — even in summer, temperatures inside the tunnels are between 12–15°C.

Can I join as a solo traveler?

Yes! Contact us and we’ll help you join an existing tour group.

I have more questions

Visit our full FAQ page for more answers, or contact us anytime — we’re happy to help.

Trusted By Travelers

Verified by TripAdvisor & GetYourGuide

Our tours are rated highly by travelers across TripAdvisor, GetYourGuide, and Google Business. Guests praise the unique experience, professional guides, and unforgettable underground adventure.

Ready for the Adventure?

Discover the mysteries of Zeljava Airbase and join a guided adventure that’s truly unforgettable.

Reserve Your Spot

Thrill quest takes you on guided underground adventures at Zeljava Airbase.

Languages

Site map

Contact Us

Plitvice, Croatia

+385 99 840 35 36

info@thrillquest.hr