The Cabinet War Rooms are an underground complex that had been used as an operational command and control centre by the British government throughout the Second World War. Located beneath the Treasury building in the Whitehall area of Westminster, the facilities were abandoned in August 1945 after the surrender of Japan. The Rooms were opened to the general public in 1984, having previously been managed by the Department for the Environment.
The Cabinet War Rooms became operational in 1939 and were heavily used by Winston Churchill during World War II. Engineered as a bunker, the facility was reinforced with a layer of concrete, one to three metres thick referred to as 'the slab'". Over 100 meetings were held in the Cabinet War Rooms between 1939 and 1945.
The section of the War Rooms open to the public is only a portion of a much larger facility. They originally covered three acres (12,000 m²) and housed a staff of up to 528 people, with facilities including a canteen, hospital, shooting range and dormitories. The centrepiece of the War Rooms is the Cabinet Room itself, where Churchill's War Cabinet met. The Map Room is located nearby, from where the course of the war was directed. It is still in much the same condition as when it was abandoned, with the original maps still on the walls and telephones lining the desks. Churchill slept in a small nearby bedroom although he only slept in the war rooms for three nights over the course of the war. One feature of the bunker was a telephone scrambler system that allowed Churchill to securely speak with President Roosevelt in the White House. The unit was concealed as the Prime Minister's lavatory.