Cymbeline's Castle is the remains of a motte-and-bailey

Motte-and-bailey

A motte-and-bailey is a form of castle, with a wooden or stone keep situated on a raised earthwork called a motte, accompanied by an enclosed courtyard, or bailey, surrounded by a protective ditch and palisade...

 castle

Castle

A castle is a type of fortified structure built in Europe and the Middle East during the Middle Ages by European nobility. Scholars debate the scope of the word castle, but usually consider it to be the private fortified residence of a lord or noble...

 in woods north of Great Kimble, Buckinghamshire

Buckinghamshire

Buckinghamshire is a ceremonial and non-metropolitan home county in South East England. The county town is Aylesbury, the largest town in the ceremonial county is Milton Keynes and largest town in the non-metropolitan county is High Wycombe....

, England. 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 Kimble villages (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 you run around this mound seven times, the devil

Devil

The Devil is believed in many religions and cultures to be a powerful, supernatural entity that is the personification of evil and the enemy of God and humankind. The nature of the role varies greatly...

will appear.