Gin Head, sitting on a promontory near North Berwick, was set up by the Admiralty during the Second World War to frustrate Luftwaffe attacks on our shores.
It even played a lead role in preparations for D-Day, tricking the Germans into thinking the invasion would happen in the Pas-de-Calais.
When Gin Head’s derelict laboratories went on the market in 2015, an asking price of £3.5 million was invited. However, four years later, anyone looking for an impregnable James Bond-style lair can have it for £2.5m.
The property comes with planning permission for a stunning “Grand Designs” house dreamed up by a leading firm of Italian architects.
Estate agent Rettie describe it as “one of the most visually compelling sites in Scotland”.
It adds: “It is surrounded by sensational rock formations, emerald cliffs and mesmerising, infinite seas.”
The nearest neighbour is the ruins of Tantallon Castle, perched on another clifftop 300 metres to the east of Gin Head.
For all its nondescript design, Gin Head played a starring role in developing the “dark arts” of warfare during the Second World War.
Dozens of scientists worked tirelessly to intercept communications between enemy destroyers and U-boats.
Its greatest success was in the creation of technology, used to trick the Germans into thinking the 1944 D-Day landings would take place far from Normandy. The researchers also came up with a system of dropping aluminium foil from aircraft to jam signals to enemy radar stations.
The buildings were still in use by the Admiralty up until 1984, when it was sold to a major defence contractor.
It is being offered along with almost six acres of surrounding land.
As well as the scheme to develop one single home, Gin Head comes with planning permission to create seven contemporary homes on the site.
The 26,000sq ft space is alive with possibilities – myriad bedrooms, studio space, a luxurious cinema, an Olympic-size swimming pool and sky-lit living areas.
The location offers commanding views across the Firth of Forth.
Rettie said: “Gin Head offers a wealth of opportunities to create one or more properties in a location with ever-changing, mesmerising views.”