Top secret military bunker opens to the public

It was one of the UK's largest military bunkers, built to handle top-secret information gathered by spy planes during the Cold War.

But on Friday, of the public will be granted rare access to the disused fort at Alconbury Weald, near Huntingdon, Cambridgeshire.

The former classified Avionics Building was completed in 1989 - the same year the Berlin Wall fell - and was only in operational use for a short time.

"The Cold War is such an interesting period of our recent history," said Natalie Leigh-Brown, of Urban and Civic, the housing developer of the old RAF and USAF airbase.

"Lots of things happened; you just couldn't see them.

"It was an incredible period of time for history, brinkmanship, and this building really brings all that to life."

The Grade II-listed bunker was situated at RAF Alconbury, on a part of the site sold off for housing by the Ministry of Defence.

However, the RAF base still remains operational as a site for some US Air Force operations.

The bunker was designed to withstand biological and chemical attacks.

It was never meant to be a place where people fled to safety, but housed decontamination areas and workshops so intelligence collected by TR-1 reconnaissance aircraft could be analysed.

"On the TR-1, there would have been a nose cone. That nose cone would have been taken off and then brought into this building for work," Ms Leigh-Brown said.

Due to the highly sensitive nature of the work, few photos existed of the bunker's operations, she said.

The free tours, which must be booked in advance, have been organised as part of the first national Cold War Heritage Week.

About 6,500 homes will be built on the site, alongside schools, business properties and parks.

However, there are plans for the bunker - dubbed "Magic Mountain" - to form part of a heritage park area, together with four TR-1 plane hangars.

Ms Leigh-Brown said due to the ongoing building work, any such development could be five years away, but objects from the bunker had been preserved in anticipation.

"We've got loads of items - all the way from light switches to showers - so when we're ready to have the museum, we've got everything already," she said.

"It's a living history, and if we don't preserve it, it will be lost for the world."

Follow Cambridgeshire news on BBC Sounds, Facebook, Instagram and X.