Apparently there is supposed to be an arms cache buried inside the embankment approaching Laindon railway station. The station is on the C2C line into London which was the London, Tilbury, Southend line during the war.
My Father did have documents confirming the cache although the exact whereabouts have been lost. It was sealed during the war and has remained so to this day. The area is heavily wooded and overgrown and on Railway land which probably accounts for it being untouched.
Explosives and Thompson sub machine guns were put into oil drums and sealed and still sitting somewhere on the embankment.