Cymbeline's Castle, also known as Cymbeline's Mound and Belinus's Castle, is the remains of a motte-and-bailey castle in woods north-east of Great Kimble in Buckinghamshire, England. It is scheduled under the Ancient Monuments and Archaeological Areas Act 1979. The motte is about 42 m in diameter and encircled on three sides by a ditch, outside which lie two additional baileys. Within the baileys have been found pottery fragments of the 13th–15th centuries, and Iron Age and Romano-British fragments have been recovered to the east of the remains. A short distance to the west are remains of another motte-and-bailey castle, along with a moated enclosure and a Roman villa. The name associates it with the ancient British king Cunobeline (Cymbeline), although this may be a Victorian invention. (There is also a theory that the nearby villages of Great Kimble, Little Kimble and Kimble Wick are named after Cymbeline; however, this has been discredited, as the etymology of Kimble is a description of the hill rather than a name. ) It is said that if one runs around this mound seven times, the devil will appear.

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