Geograph - photograph every grid square

Spring Quarry was requisitioned by the Ministry of Aircraft production for use as a WW2 shadow factory and became the largest underground factory in the world.
The West Lung area was never developed as intended for war use and in 1954, the workings immediately to the east were selected as the site for the top secret Central Government War Headquarters designed to accommodate the Prime Minister and 4,000 civil servants in the event of a nuclear war. The West Lung was retained to assist with air circulation but since no further development took place, it remains frozen in time with stone still suspended from cranes and 19th century miners' artefacts in abundance. It is a scheduled monument and access is not possible.