The Guardian has found official papers that tell of a secret torture center run by the British government during the Second World War. The torture center, known as "the London Cage," was operational from July 1940 until September 1948, three years after the end of the war. Over 3,500 people went through the center, being beaten, doused with cold water, forced to stand for long periods, threatened with unnecessary surgery, sleep deprived, starved, and more so that the British could gain information from them. The torture center was housed in three mansions in Kensington Palace Gardens, one of Britain's most expensive and exclusive streets.