Dolcoath Mine, ( English : " Old Ground Mine " ), the'Queen of Cornish Mines'was, at a depth of 3, 500 feet ( 1, 067 m ), for many years the deepest mine in the world, not to mention one of the oldest before its closure in 1921.
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Shoeburyness is where, during the Second World War, a magnetic ground mine, which was deposited in the mud at the mouth of the Thames by the Luftwaffe, was discovered by the MOD . Up until that time, various sinkings of ships around the English coast were thought to be due to U-Boat torpedoes.
