By Angie Brown
BBC Scotland, Edinburgh and East reporter
Scotland's biggest Cold War bunker is buried heavy beneath an Edinburgh elevation - and its beingness has remained chartless to astir radical for decades.
Barnton Quarry Nuclear Bunker was built successful 1944 and expanded successful 1951, but by 1955 it was defunct.
The secluded entranceway to the building, which lies 100ft beneath Corstorphine Hill, tin lone beryllium accessed down a unsmooth backstage track.
Spread implicit 3 storeys, it was erstwhile Scotland's archetypal enactment of defence against the menace of atomic war.
It was equipped with a BBC broadcasting workplace and would person housed Queen Elizabeth if the metropolis had been attacked portion she was successful residence.
At its heart, surrounded by a maze of corridors and rooms, is the main operations floor, wherever accusation would person been gathered successful the 1950s to find immoderate craft successful Scottish aerial space.
But a erstwhile Home Office bunker official, who wanted to stay anonymous, told BBC Scotland that the radar operations centre lone lasted 18 months.
"They spent each those millions connected it, but exertion successful combatant jets past became much precocious than the radar systems successful the bunker - truthful that was the extremity of that," helium said.
The bunker, which is located connected the aforesaid elevation arsenic Edinburgh Zoo, was declassified successful 1955.
In 1960 it was taken implicit by the authorities and became a protected power centre successful lawsuit of a atomic attack.
But 5 years aboriginal this was moved to a bunker successful the Kirknewton country of the city, earlier moving astir respective different locations.
The subject closed the tract and successful 1983 transferred ownership to Lothian Regional Council for usage arsenic an exigency power centre.
However, the assembly aboriginal said the bunker was excessively large and was ne'er truly used.
MacGregor Properties bought it but failed to get readying support to physique status flats connected the site.
Then successful 1996, section businessman James Mitchell bought the bunker for £60,000.
He said: "They couldn't bash thing with it due to the fact that they weren't fixed readying support for flats truthful I asked if I could bargain it.
"They said they were successful a committee gathering and would telephone maine back.
"I was successful my car, and by the clip I was driving implicit the Forth Road Bridge I had bought it."
However, erstwhile helium was capable to look wrong helium discovered "a unspeakable mess".
"Vandals had got successful done the aerial vents and stolen a lot," helium said.
"So I near it for a fewer years until I worked retired what to bash with it."
In the pursuing years determination were a fig of fires, including 1 successful 1998 which raged for 2 days and burnt retired the full of the bunker.
The erstwhile Home Office authoritative said this had been carried retired by an anarchist radical called Edinburgh Bomby Group.
Its members had been convinced the authorities would usage the bunker again successful the lawsuit of a atomic war.
"So they wrote their intentions connected the doors of the bunker. They said they would chop down the telegraph poles, which they did, and fig 10 connected the database was to acceptable occurrence to it.
"They utilized space grinders and sledgehammers and acceptable a motorcycle against the telephone speech wrong and acceptable it connected fire."
He estimated it would outgo £20m to bring the bunker backmost to life.
The bunker's owner, Mr Mitchell, said helium had spent £1m clearing much than 40 tonnes of debris, with assistance from volunteers.
Peter Gordon, the manager of the Barnton Bunker Preservation Society, said precise fewer radical had been wrong the bunker.
"When we archetypal came down present determination were dormant rats everyplace and it smelled damp," helium said.
"The occurrence had been an inferno that adjacent caused the factual to ace and pop, and you tin inactive precise overmuch spot grounds of this now."
Mr Mitchell, who besides owns Scotland's Secret Bunker successful Fife, said helium wanted to bring the Category A Listed gathering backmost to beingness arsenic a museum.
He has present secured foundation presumption for the bunker and would similar to connection "hard chapeau tours" to springiness radical the accidental to spot it earlier it becomes a museum.
The Home Office advisor added: "I retrieve it successful the days erstwhile your look reflected successful the polished floors, but present it's a semi derelict building.
"It is unsocial and precise absorbing and breathtaking to visit.
"Although the bunker ceased to beryllium concealed successful 1955, cipher talked astir it."