The English stately home where Nazis were tricked into spilling their secrets

And upscale he certainly did. “The whole mansion block and stable block were wired for sound,” historian Helen Fry, author of The Walls Have Ears, tells the BBC. Microphones were hidden in everything from plant pots and light fittings to the billiards table and even in trees in the grounds. Concealed wires that ran behind panelling and under the floorboards connected them to the miked rooms, known as “M” rooms, in the basement, which have been recreated by the museum, where the secret listeners, at first British German speakers, would eavesdrop night and day.