IT IS known locally as the golf ball - but this former military base once served a very serious purpose.
The facility at Balado Bridge, Kinross-shire, is a familiar landmark to motorists driving along the M90 motorway between Edinburgh and Perth.
It was opened by Princess Anne in 1985 and served as a signals post for NATO forces charged with protecting the UK at the height of the Cold War.
But the collapse of the Soviet Union just six years later greatly diminished its importance.
The MOD moved out in 2006 and it was bought by Bob Ferguson, an entrepreneur, for just over £500,000.
These revealing pictures were taken by photographer and urban explorer Ben Cooper for his Transient Places blog.
Mr Ferguson has now decided to sell up and has put the entire site on the open market, with a guide price of £1.1 million.
Estate agents describe the base as “nine acres of prime development land in a beautiful rural setting close to the villages of Kinross and Milnathort”.
Several potential uses for the land have been touted, including a retirement home, a storage depot or even a pitch and putt course.
The 60ft spherical structure known as the golf ball masks a sophisticated broadcast antenna, once linked to the former military command centre at Pitreavie, near Dunfermline, by microwave transmitter.
It facilitated long-distance secure broadcasts between Nato forces and was an integral part of the defence satellite communications system of the United States Air Force.
But its tasks have all been transferred to the Faslane naval base on the Clyde.