For the generation to whom the Cold War means more than just the period of political history between the end of the last world war and the 1980s when nuclear war seemed a real possibility, a visit to Scotland’s so called “Secret Bunker”, at Troywood in Fife, is a pretty scary experience.

This was the base from which, in its early days, the appearance and trajectory of incoming nuclear weapons was to have been tracked. Later it became the command centre for managing the post-attack phase in Scotland.

It was a considerable engineering feat. Built in a 40 metres deep hole of concrete 3m thick and reinforced with carbon roads, the bunker was designed, at its busiest, to be an entirely self-contained safe haven for 300 people. As well as living accommodation, there were operations rooms, a broadcasting studio, switchboard, special secure rooms where high level decisions could be made, and a chapel to provide solace and opportunities for reflection in what would have been times of devastating strain.

From the moment you walk down its 150-metre entrance slope you’re back in a time when the “four minute warning” seemed a tense reality and the lack of real preparation and information for the general public a scandal.

Peter Watkins’ 1966 film The War Game, which is shown in one of the cinemas now in the bunker, can still send a chill through viewers who lived through the Cold War. It must make very stark viewing for young people studying the the period as a piece of political history.

They might be equally disturbed by the instructions for how to deal with anyone who died while their family was sheltering from nuclear fall out - “wrap the body in a blanket and put it outside” - and the calm and unemotional way people working in the bunker were expected to deal with the horrors outside.

Although the rooms are not “just as they were left”, each has been structured and equipped to give a clear idea of what it might have been like during its various phases of operation.

Having begun as a radar base for the Royal Observer Corps it was sited at Troywood because of the proximity of the Royal Navy base at Rosyth and the RAF station Leuchars.

Later it became a regional seat of government staffed by the Civil Defence Corps. In its final metamorphosis, the bunker became a regional government headquarters in which ministers and civil servants could develop strategies for supporting the civilian population after a bomb had been dropped.

It is a measure of how quickly the nuclear threat crumbled that the refurbishment of the bunker that was due in 1992 was cancelled and, in a modern day version of “swords into plough shares”, this sinister building with all its devastating implications became a museum in 1994.

In each of the rooms there are good explanations of their purpose and the procedures that would have been followed. Several also have continuous loop videos which either simulate the way the room might have been used and what decision would be taken there, or give some other background to what would have been happening in the event of nuclear war. There are also three cinemas showing informative films.

The sinister atmosphere is enhanced by the continuous background chatter coming through the loud speakers, occasionally interspersed with announcements such as “BBC engineer to the broadcasting suite, please”. It makes the past very much present, especially when there are few visitors to provide real human voices.

One mystery remains. How could a construction on that scale have been carried out without the knowledge, as it is claimed, of local people? If it’s true that no spy or Russian agent knew of its existence either, then “secret” might be a fair description. But that seems unlikely in the age of feverish suspicion that made such places necessary.

The Secret Bunker, Troywood, Fife, Scotland. Contact the Underground Nuclear Command Centre, Crown Buildings, near St Andrews KY16 8QH. Tel: 01333 310301. April to end of October. Book first. pound;2 per pupil