Monkton Farleigh Underground Ammunition Depot

On the site of an old abandoned underground quarry lies the biggest WW2 ammunition depot in Europe. Started approximately in 1936, and was used right until the 1950s. The expenditure in the 1940s alone is estimated to be in the region of 49 million pounds, old money (roughly 5 billion nowadays). It was simply enormous, covering some 80 acres underground and during its heyday it could house over 12 million tons of ammo.

The entire site above ground was constructed in such a way that it would not be seen as an ammo depot by enemy reconnaissance. The trains that brought ammo to the site would be seen to enter a tunnel at Box Hill nearby and then apparently exit it as normal. However, it was a different train that would exit the tunnel – the original train was still in the tunnel unloading its ammo, undetectable to enemy aircraft. This would then be delivered to Monkton Farleigh via aerial ropeway and into the various sites within the complex through a system of narrow gauge railway tracks and conveyor belts.

Also within the complex were air shafts, with ventilation facilitated by huge fans, workshops, power plants and, in certain areas, de-contamination centres.