Riding around an abandoned Nuclear proof air base

We moved quickly through Central Europe only stopping in Germany and Italy. We had a long way ahead of us and a reasonably tight schedule. We saw lots of of autobahn and autostrada for the first few days which was a little boring but once leaving Italy we entered first Slovenia and then Croatia. I have never been to these countries so as we crossed the Italian/ Slovenian border the trip really began for me as I was venturing into the unknown for the first time.

Slovenia is a small country and we just popped across the South Western corner in a couple of hours. I definitely didn’t see enough and would love to one day go back there and really get to explore the country as what I saw was lovely.

On entering Croatia we planned to head up into the mountains to visit an old Yugoslav Cold War era air base on the border with Bosnia. Built in the 1960’s the aircraft hangars are actually 4km long nuclear blast proof tunnels built straight into the mountain. The Information I had was sketchy and included reports of rogue landmines littering the area but I had heard we could enter the tunnels if we could find the base!

Just as we entered Croatia we stopped at the first available petrol station for fuel and some refreshments. It was at this moment I realised all was not right with my digestive system and I began to feel extremely nautious. I instantly knew the identity of the culprit. At our last stop in Trieste my kebab was a little too rare for my liking and now I was facing the consequences.

From our current location we had at least a two and a half hour ride to reach our hotel at the Plitvice Lakes near to the Bosnian Border. This was not good as I was becoming very ill, very fast but we had a strict schedule to reach our next hotels and I didn’t want to miss out on a chance to visit the base so downplayed my illness to Jenny and her Mum and Dad who were joining us on the stretch down to Turkey.

With this in mind we set off in earnest and I concentrated on chatting to Jenny over the intercom to keep me from concentrating on my sickness however I found it increasingly hard to talk. About half way into the journey i had to get off my bike and stagger into an area of rough ground and throw up. I took a nap for around 20 mins and then somehow we continued, finally reaching the hotel around 3pm. However I can only recount this with the help of Jenny as I don’t really remember anything! I awoke groggily the next day to everyone having breakfast and remarkably I felt functional if weak. I was feeling pretty excited actually as it would have been a travesty to make it this close to the Zeljava complex and not actually get to investigate!

After breakfast we packed up the bikes and set off on our 20 minute journey to where my gps track showed the entrance to the base. Even though the base was such a huge complex with vast underground features it has never been turned into a museum and has been left to overgrow. In the UK such a place would be under extreme security to stop inquisitive people from entering and accidentally getting injured or it would have been transformed into a museum with a hefty price tag on entry but not here. Once we leave the main highway we pass through small run down villages. As we near the main entrance the houses become increasingly abandoned and run down. Strangely there does not appear to be a grand entrance as is seen with most other cold war facilities but we just sort of come across the overgrown barracks and administrative buildings.

The narrow tarmac leading between them is cracked and covered with dirt and gravel however the building are quite intact. We follow the tarmac road for a couple of hundred meters where we are greeted by the imposing outline of a Douglas C47 aircraft! The C47 is a world war two era allied transport aircraft that was flown in nearly every battle. Unfortunately this one has seen better days and has had many parts taken as trophies such as the propeller blades, flight instruments etc. It also appears to be regularly used as target practice by hunters and is adorned with bullet holes and traveller stickers. This is a little sad as the photos I had seen from only a couple of years earlier showed it in much better condition. Still someone had made a rough wood ladder and we were able to climb on board and take a look!

After a short photo shoot we set off along the abandoned access road towards the runways. At this point we came across the first warning sign for land mines in the area and decided as a group that we must not stray off the tarmac at all costs! A little further on and the narrow tarmac road opened up into a huge tarmac area and as the trees ended we found ourselves in the middle of the junction between the two intersecting runways and to our right, cut straight into the face of the imposing mountain we saw the large concrete entrances to the vast underground hangar complex!

We stopped to look along the runways. Heading straight out from the tunnels is the largest tarmac runway which is easily a 30 metres wide and goes as far as the eye can see into the distance. At 90 degrees is the narrower runway. What is quite crazy is how wavey the runways are! They rise and fall in quite aggressive peaks from this viewing angle and Brian and I joke about the strength of a MIG 21’s undercarriage! We park the bikes closer to the tunnels with myself and Jenny at the first tunnel and Brian and Sue choosing to venture into the second tunnel.

I dig out my trusty headtorch and we head to the entrance. The tunnel entrance is an arch about 10 metres high however it is partially enclosed by concrete and has a cutout at the top for the tails of the aircraft. We climb up and over the large pile of gravel and rubble that has been dumped at the opening to stop smugglers vehicles entering and we are met with a distinctly musty, damp and cool atmosphere. It’s pitch black inside and the large pile of rubble and restricted entrance doesn’t let much light in but as our eyes adjust we can see that that the tunnel is huge, maybe 30 metres across and extends far into the mountain following a gentle curve.

We follow it for about a hundred metres and then we realise that we no longer can see the roof! We have entered a huge cavernous room! It even appears to have a small building of its own in the back corner. The head torch struggles to reach the furthest corner. Immediately to our right we can feel the gentle motion of air and we see the remains of the 100 ton nuclear proof blast doors. The base saw extensive fighting in the 90's and as a consequence much of it was destroyed by the use of over fifty tons of explosives to stop it being used by enemy forces. As a result the huge blast door has been ripped open and deflected upwards with all of its rebar sticking out like some kind of post apocalyptic octopus.

What is weird is that the floor remains barely touched by the blast and all of it seems to have been focused on the doors. We spend the next 20 minutes taking some photos. We take a little walk into the huge tunnel behind the blast door but there is nothing to see. The torch cannot see further than a hundred or so metres and as i recall reading about the facility this hangar tunnel is nearly 2km long! Somewhere inside is the command complex as well as a huge dining hall and rooms for storing munitions but we are a little freaked out and don’t have spare torches so decide to return to our bikes. Brian and Sue have already set off to find our hotel in the lovely seaside city of Zadar and Jenny and I follow suite. We decide to say goodbye to the base by riding half a mile down the main runway together before turning around leaving from where we entered. We would both love to return one days as it is such a strange and creepy place. Weirdly it is also very quiet and calming to be there. I would say that I cannot recommend visiting the area due to the risk of injury from land mines and from the dangerous state of the complex from all the bombing!