Another of the castles of Robert of Rhuddlan was DEGANWY, or Gannoc, which defended the mouth of the Conway.[843] Here it is said that there was an ancient seat of the kings of Gwynedd.[844] The two conical hills which rise here offer an excellent site for fortification, one of them being large enough on top for a considerable camp. The Norman Conqueror treated them as two mottes, and connected them by walls so as to form a bailey below them. The stone fortifications are probably the remains of the castle built by the Earl of Chester in 1211.[845] This castle was naturally a sorely contested point, and often passed from hand to hand; but it was in English possession in the reign of Henry III. It was abandoned when Edward I. built his great castle at Conway. With its usual indifference, the Survey mentions no castle in Flintshire, but we may be sure that the castle of MOLD, or Montalto (Fig. 40), was one of the earliest by which the Norman acquisitions in that region were defended,[846] though it is not mentioned in authentic history until 1147. The tradition that it was built by Robert de Monte Alto, one of the barons of the Earl of Chester, is no doubt correct, though the assumption of Welsh legend-makers that the _Gwydd Grug_, or great tumulus, from which this castle derives its Welsh name, existed before the castle, may be dismissed as baseless. The motte of Robert de Monte Alto still exists, and is uncommonly high and perfect; it has two baileys, separated by great ditches, and appears to have had a shell on top. [D. H. M.] The castle was regarded as specially strong, and its reduction by Owen Gwynedd in 1147 was one of the sweetest triumphs that the Welsh ever won.[847] [Illustration: FIG. 40.--MOTTE-CASTLES OF NORTH WALES. Mold. Welshpool. Wrexham. Mathraval.]