IN the 1980s I was so fearful of the threat of an all-out war between the American and Soviet superpowers that I took my first, and to date, only steps down the road of political activism by deciding to join the Campaign for Nuclear Disarmament (CND).

With my best Oxfam overcoat, wedge haircut, vague moustache and stretch jeans I took myself off to the local meeting – but my mate didn’t turn up and I was too scared to go in by myself so I went home without ever going across the doorstep.

Instead, I took to just wearing the ban the bomb badge which, to be honest, was always the most attractive part of the whole venture.

I was reminded of this as more than two decades later I travelled to the Secret Nuclear Bunker at Kelvedon Hatch, Essex, which was originally built in 1952 as an organisational headquarters for the aftermath of a nuclear strike.

Thankfully it was never needed for that purpose and has since been sold off and opened to the public.

With Russia once again flexing it’s military muscles and stretch jeans back in fashion - albeit with no chance of me getting into them now – it was the perfect time to visit.

My companions for the trip were my sons Aidan, eight, and four-year-old Zak.

What at first looks like a normal bungalow is actually the front for a maze of rooms built into a hillside and protected by thick concrete and steel blast-proof doors. There are a few military vehicles outside to look at now.

At first the bunker was to be a key RAF base from where the reaction to a nuclear attack on Britain would be organised before changing to a regional government headquarters dealing with the survival of the civilian population.

I’ve dragged Aidan and Zak to war museums and battlefield site from Dunkirk to Agincourt - without too much complaint - and they were keen to come along We all picked up the handsets which provide and audio guide to the bunker, but the children’s constant questioning made it impossible to follow the audio trail properly so I soon gave up on it.

The bunker is built over three levels and was designed to accommodate 600 military and key civilian personnel. With a surface devastated by the nuclear strike and the resulting fall out they would have been underground for some time.

The tensions they would have been under would have been almost unbearable. A lack of bed space meant a system ‘hot bunking’ - or sleeping in shifts in the dormitories - would have been in place.

As we walked deeper into the bunker we came across command rooms, full of banks of computers, from where workers would have tried to make sense of the chaos above them. For obvious reasons, the structure had to be self-contained with food and water supplies. The power generators can be seen.

The military command room would have been the centre of Britain’s retaliation to the attack while scientists monitored the blast and predicted fall-out patterns. There was also the vital task of communication with the outside world and the bunker contains a broadcast studio and telephone exchange.

Along the route through the bunker, television play information films from the Cold war era. We stopped to watch one of the ‘Protect and Survive’ series narrated by Patrick Allen, who according to his obituary, made a tidy profit from such voiceover work, including 70s Barrett Homes adverts.

Some of the advice, such as building a makeshift bomb shelter from a table surrounded by bags of earth, seems laughable now. Would it have worked? Probably not, but it made you feela litter better as you waited for the three minute warning to count down.

A large part of the bunker’s charm and appeal is that it appears to be have been left pretty much as it was when it was operational. It is a fascinating look inside a building that hardly anyone knew existed at the time.

As I mentioned, my children have been to many military museums so it was surprising to hear Zak say he wanted to leave. His requests became more frequent when we saw a dummy dressed in a WRAF uniform and by the time we came across a model dressed in a full radiation suit and mask he was rooted to the spot by fear.

I decided to cut the visit short at that point and head for the cafe where Zak even refused the offer of a drink and a muffin - he must have been scared. I’m sure it was one-off and he cheered up soon after but you may want to take it account if you visit with very young children.

The cafe also houses a shop where souveniers, books and militaria are available. With ample car parking, a picnic area and animals including rabbits, guinea pigs and even the odd lama to look at, a trip to the Secret Nuclear Bunker is a good day out. It is educational informative and well-worth a look.

Admission: Adults £6.50, five to 16-year-olds £4.50, family ticket (two adults, two children) £16