Deep in the bowels of the Adriatic hills, far from the eyes of tourists sunbathing on nearby beaches, lie forgotten giants of a bygone era. The tunnel cisterns of the former Yugoslav People's Army represent fascinating remnants of a time when the Adriatic was strategically protected as the most important national resource. Today, these underground labyrinths attract urban explorers, history enthusiasts, and all those seeking something more than a classic seaside holiday.
What exactly are JNA tunnel cisterns?
During the Cold War, Yugoslavia built an impressive network of underground fuel reservoirs along the entire Adriatic coast. These facilities served to supply the navy and air force, and their strategic position was no coincidence – hidden in the hills, protected from air raids, with direct access to the sea through underwater pipelines.
A typical tunnel cistern consists of a main access tunnel, side chambers for fuel storage, and a complex ventilation system. Some of these facilities could store up to several thousand tons of fuel, which speaks volumes about their size and the ambition of the project.
5 most interesting locations of abandoned cisterns
1. Railway tunnel cistern near Šibenik
Not far from the beaches of the Šibenik archipelago, one of the best-preserved cisterns on the Adriatic lies hidden. The access tunnel is almost 200 meters long, and the interior is breathtaking – enormous chambers with remnants of metal structures and traces of time on the concrete walls. The location is relatively accessible, but definitely bring a strong flashlight and appropriate footwear.
Practical tip: If you're staying in one of the apartments in the Šibenik area, you can visit this location in the morning before the sun gets too strong, and spend the rest of the day on the nearby beaches of the Solaris riviera.
2. Underground complex on the island of Vis
Vis is known as a former military base closed to foreigners until 1989. That's precisely why this island hides the most military secrets, including impressive tunnel cisterns in Smokova bay. The combination of untouched nature, crystal clear sea, and mysterious tunnels makes Vis a perfect destination for those who want to combine a beach holiday with a dose of adventure.
We especially recommend visiting in late spring or early autumn when crowds are smaller and temperatures are pleasant for underground exploration.
3. Cistern in the Split hinterland
Many tourists who visit Split don't even suspect that just thirty minutes' drive from Diocletian's Palace there's an entrance to an underground world. This cistern is special for its size – the interior resembles a cathedral, with high vaults that echo with every step.
Warning: Official access is not permitted, and entry is at your own risk. Local enthusiasts sometimes organize guided tours – inquire at the hostel or apartment where you're staying.
4. Hidden tunnel near Pula
Istria, known for truffles, wine, and beautiful beaches, hides another secret. Near Pula, there's a tunnel cistern that served to supply the naval base. What makes this location special is its proximity to famous beaches – after a morning exploration, you can cool off at Hawaii (yes, that's really the beach's name!) or visit the beautiful Valovine cove.
Staying overnight in Pula provides the perfect base for combining historical explorations with classic Adriatic pleasures. The Arena, fish taverns, and sunsets over the sea – everything is within reach.
5. Cistern near Zadar
The Zadar hinterland hides several smaller tunnel facilities that served as backup locations. Although smaller than the previous ones, these tunnels offer a more intimate atmosphere and better accessibility. They're especially interesting for photographers who find inspiration for unique shots in the play of light and shadow.
After exploring, definitely visit Zadar's beaches – Kolovare for a family atmosphere or hidden coves on Ugljan reached by a short ferry ride.
Practical tips for exploration
What to bring with you
- Lighting – a quality headlamp is essential, and we recommend a backup as well
- Appropriate footwear – closed shoes with non-slip soles
- Water and food – there's nothing in the tunnels, and exploration can take a while
- First aid – a basic kit just in case
- Charged phone – for photos, but also for safety
When to visit
The ideal time for exploring underground facilities is early morning or late afternoon during warmer months. Temperatures in the tunnels are constantly low (around 15°C), which provides refreshment during hot summer days but requires a light jacket or long-sleeved shirt.
Spring and autumn offer the perfect balance – fewer tourists, pleasant temperatures outside, and enough daylight for safer exploration of entrance areas.
Safety warnings
You explore abandoned military facilities at your own risk. Never enter alone, always inform someone where you're going, and watch out for structural stability – some facilities have been deteriorating for decades. Also, respect local regulations as some facilities may be on private land or marked as dangerous.
Combine adventure with relaxation
What makes the Adriatic coast unique is precisely this combination – in the morning you can explore dark tunnels full of history, and in the afternoon lie on a sunny beach with a glass of local wine in hand. Few destinations in the world offer such contrast.
Finding the perfect accommodation that serves as a base for both types of activities is key to a successful holiday. Apartments in smaller towns are often closer to hidden locations, and local hosts can be an invaluable source of information about secrets not written in any guidebook.
Conclusion
Abandoned JNA tunnel cisterns represent an unexpected but fascinating addition to any holiday on the Adriatic. They are a living reminder of the turbulent history of this region, but also an invitation to adventure for those who want to look beneath the surface – literally and metaphorically. Next time you're sunbathing on one of the beautiful Adriatic beaches, remember that somewhere in the hill behind you there may lie an entrance to a completely different world.