The Central Government War Headquarters (CGWHQ) is a 35-acre (14 ha) complex built 120 feet (37 m) underground as the United Kingdom's emergency government war headquarters – the hub of the country's alternative seat of power outside London during a nuclear war or conflict with the Soviet Union. It is located in Corsham, Wiltshire, in a former Bath stone quarry known as Spring Quarry, under the present-day MoD Corsham. In 1940, during the Second World War, the site was acquired by the Minister of Aircraft Production and used as an underground engine factory.