Britain's Prince Charles has launched a Â£1.8 million appeal to restore Bentley Priory.
The historic site is a former headquarters of the Royal Air Force's Fighter Command and was the nerve centre from which the Battle of Britain was co-ordinated in 1940, during World War II.
The future of the building has been uncertain since 2007 when it was named surplus to Ministry of Defence requirements.
The Prince of Wales' grandmother, Queen Elizabeth the Queen Mother was a regular visitor to the priory during the war and she passed on her admiration of the building to the heir to the throne.
Writing in the Daily Telegraph newspaper, Prince Charles - who is patron of the restoration fund - said: "Bentley Priory is an iconic building with rich historical significance, not least as the home of Fighter Command during the Battle of Britain.
"The Priory's architectural merit, which owes much to the work of Sir John Soane, makes it an obvious candidate for restoration.
"The restoration of important buildings is both a time-consuming and expensive business, but their preservation adds greatly to the important heritage, and fabric, of our country, and to the continuation of our 'island story'.
"I am hugely encouraged by the creative way in which the Bentley Priory Battle of Britain Trust has worked, with assistance from my Regeneration Trust, to forge an innovative partnership with the developers - one which I hope can serve as a blueprint for similar heritage projects in the future."
The Grade II listed building which is the priory was made famous in the 1969 film 'Battle of Britain', in which the character 'Stuffy' Dowding, played by Lord Olivier, was seen watching London burn from the Priory's balcony.
If the priory gets the money it needs for the restoration visitors will be able to see the restored office in which Lord Dowding worked shifts gathering intelligence and deciding how to deploy pilots.