This is the story of a secret underground wartime factory in a very unusual place in Britain's capital. Interesting Sh!t's Steve Hulford had a chance to visit.

Join Steve on a tour through the tunnels of Gants Hill tube station in London, UK. During WWII, the station was used as an air raid shelter and the tunnels as a munitions factory for Plessey electronics. Plessey opened their facility in 1942, and production lasted until 1945 before the station was opened for public transport on 14 December 1947.