The bunker was built in the 1950s for local government officials
A derelict nuclear bunker near Cheltenham has failed to find a buyer
The building on Leckhampton Hill went up for auction on Wednesday, but failed to reach its reserve price of £400,000.
It was bought by the county council in 1963 and was put on the market last summer as "surplus to requirements".
The council says it is disappointed the site has not been sold, but is confident a buyer will be found soon.
The two-floor bunker was built in the 1950s on a site used during the First and Second World Wars as a US military hospital.
It occupies an elevated position on the Cotswold escarpment, offering commanding rural views and was intended to provide a protected centre for local government at the height of the Cold War.