A former nuclear bunker made redundant by the end of the Cold War failed to sell at auction on Friday.
The complex has 50 rooms
The 50-room complex in Goosnargh, Lancashire, was built during World War II and refitted during the Cold War to act as a military command centre.
Lincoln-based chartered surveyors JH Walter had hoped to make £250,000 but it even missed its reserve price.
Rob Ward, of JH Walter, said: "We will continue to market the bunker, it is very much still on the market."
Mr Ward said the property was close to reaching its "realistic" reserve price during the auction at the Bentley Hotel in Lincoln.
"I would imagine some of those potential buyers were not able to attend the auction and the ones who did were not prepared to go quite far enough," he said.
The 15,000 sq ft building was one of two national headquarters of the United Kingdom Warning and Monitoring Organisation and the Royal Observer Corps Group HQ.
It has 50 rooms on two floors ranging from operations room to dormitories behind blast proof doors.
There is a restaurant-sized kitchen and canteen and the bunker also features decontamination rooms, water tanks to supply the complex for months and a huge air filtration system dating from the height of East-West tensions.
It began life as one of four bunkers built for RAF Fighter Command in 1940 but by the 1960s had been refitted to survive a nuclear bomb.
Mr Ward said former nuclear bunkers have been used for anything from a recording studio to the base of an internet security firm.