FOR nearly 50 years, it has been a mystery to all except those who worked there. But now, the secret story of York's nuclear bunker is being revealed to the public.

After six years of meticulous work, English Heritage has restored the Cold War bunker in Monument Close, Acomb, so it appears almost exactly as it did when it was decommissioned.

The property, officially entitled No 20 Group Headquarters, was built in 1961, and volunteers from the Royal Observer Corp (ROC) were on constant standby until its decommissioning in 1991.

At a media event yesterday, former bunker personnel recalled what life was like beneath the ground and on high alert.

David France, the bunker's deputy commandant from 1986 to 1989, said: "We always said that we trained to do a job that we hoped we should never have to do."

Mr France, 77, was involved in a number of annual 24-hour exercises at the bunker, where crews would be brought in to simulate how they would respond to a nuclear attack.

If a crisis were to occur, a crew would be brought in to the bunker, where they could remain for up to two weeks.

Mr France said having to leave family members behind was "always in your mind", but said volunteers would look out for each other's relatives.

He said: "Those who were off-duty would look after the families of those who were on-duty. There was a camaraderie."

The bunker's official role was to monitor any attacks, collating information about type, size and precise location, as well as the nuclear fallout.

The hub of the bunker was its control room, where ROC volunteers would feed information to a team of Government scientists for analysis.

But according to English Heritage curator Kevin Booth, the bunker was also a deterrent.

He said: "If the Russians knew we had the capability to survive, they knew we had the capability to strike back.

"It's a fantastic feeling to see it open. It's a great thing to add to York, and it's a big thing for English Heritage to add to its portfolio. I have no doubt people who come are going to be astonished and bemused as well."

Former crew officer Brian Tomlinson said: "They have done an excellent job. It's more or less as I remember it."

The bunker is open to the public from Monday by pre-booked tour only. Anyone interested in visiting it should phone 01904 646940, or visit Clifford's Tower.

Updated: 08:46 Wednesday, May 10, 2006