The farmland of north-east Fife is dotted with stone cottages. Troywood, two miles inland from the fishing village of Crail, looks much like the others with its grey stone walls and red pantiled roof. But inside, you’ll find not a cosy farm cottage, but the world of the Cold War.

Troywood was one of the early warning radar stations built along the east coast of Britain after the Second World War, as relations between the Allies and Warsaw Pact countries deteriorated.

Sites near to likely enemy targets were built underground. Troywood, not far from the Royal Naval Dockyard at Rosyth and even closer to the RAF station at Leuchars, was one of the largest underground bunkers built.

It has an outer shell of three metres of solid concrete and 2.5cm-thick tungsten rods inserted every 15cm. Three tons of blast-proof doors open onto 150 metres of tunnel that leads to a labyrinth of passages and rooms which could accommodate up to 300 people. Topped off with a guardhouse built in the style of a Fife farm cottage, even locals were unaware of its purpose. As the Cold War ended, it came off the secrets list in 1993 and became a museum. Until 1956, the bunker was manned by the RAF. From 1958 to 1968, it was a regional seat of government staffed by the Civil Defence Corps. When the corps was disbanded, the bunker assumed its most important role.

The bunker was refurbished and fitted out with six dormitories to become the regional government headquarters for Scotland. Major decisions would be taken here in the event of nuclear war. There was accommodation for senior ministers, civil servants, emergency services personnel and scientists, with a suite for the Secretary of State for Scotland looking on to the nuclear operations room.

You can visit the sound studio from which BBC staff would have issued emergency broadcasts. The original switchboards, with 2,800 outside lines and 500 internal extensions, still work. They are all manual, and were staffed by 10 operators 24 hours a day.

In the cinema you can watch information films, including one about how to turn your house into a shelter. The RAF operations room is a reconstruction, using artefacts found on the site, such as a “tote” board showing aircraft and anti-aircraft gun status. Equipment that recorded Soviet incursions into British air space is displayed in the radar room.

The plant room still contains the original air filters designed to combat gas, radioactive or biological warfare particles. But today, workers and visitors are happy to breathe the fresh Fife air supplied through a normal ventilation system. New artefacts and reconstructions are constantly being introduced. Among the most recent is a reconstruction of a section of the Berlin Wall, complete with lookout.

Take a trip

For further information telephone 01333 310301 or visit www.secretbunker.co.uk

The Secret Bunker is open every day from April 1 to October 31, 10am to 5pm. Admission for school parties is pound;2.95 per head for a minimum of 10 (Other prices: adult pound;6-95 child pound;3-95; family pound;19-50.) Audio-visual facilities are available with prior booking of school parties