Helmsley Castle is located on a rocky outcrop overlooking the Rye Valley. The ruins feature extensive medieval earthwork defences, the remains of the east tower and a Tudor mansion. The site was first fortified by Normans during the 12th century. The castle was gradually extended throughout the 13th and 14th centuries, changing hands several times, with owners that included Richard, Duke of Gloucester (the future King Richard III).

It was garrisoned by royalist forces during the Civil War and was besieged from September to November 1644. The castle occupants were forced to surrender through lack of food. Like many other castles, the victorious parliamentary forces destroyed its defensive capabilities. The castle is still owned by the same family from the time of its slighting but is now under the stewardship of English Heritage.