Description

The monument comprises the remains of the outer defences of an important but short lived stone castle established by Henry III in 1241 following a documented false start on nearby Graig Fawr and comprehensively destroyed by Llywelyn ap Grufudd in 1263. Most of the inner ward and the rock below it was destroyed by quarrying during the First World War but its general layout is known from an antiquarian survey published in 1912.

It was located on a towering limestone rock overlooking the eastern bank of the lower reaches of the River Clwyd and comprised a compact, irregular inner ward at the highest point of the site a with rectangular outer ward on lower ground blocking the approach from the east and a smaller crescentic outwork to the west, the remaining sides being defended by precipitous slopes. The inner ward comprised an unusual west-facing gatehouse, apparently flanked by one round and one polygonal tower at its eastern side, two large polygonal towers facing north opposite a domestic range, presumed to be a hall and chambers. There were a series of slighter outworks and buildings to the west and south, almost all of which have been completely quarried away, with the exception of the western tip of the crescent shaped enclosure and its scarped rocky defences. The surviving outer ward is defined by a stony bank and rock-cut ditch to the north and east, where it is currently entered from a causeway crossing the ditch. There is now a tennis court to the northern side of the interior.Whilst a number of articulated fragments of well-mortared limestone masonry survive around the base of the hill there is no upstanding stonework, although the outer ward bank may represent the base of a wall and the buried lower stages of a square tower and curtain wall shown on early plans may survive in the remaining portion of the western enclosure.

Along with the extensive rebuilding of the ancient Welsh seat of Deganwy some 15 miles to the west Dyserth Castle is of historical and archaeological significance as one of two just new castles begun in Wales by Henry III of England. These were intended to support Henry's abortive invasion of Gwynedd and to control the disputed Perfeddwlad (the land between the Conwy and the Dee), and whilst building works are documented at Dyserth into the 1250s the two castles spent most of the decade under an intermittent state of siege until their eventual capture and destruction by Llywelyn. Although the relatively recent destruction of most of Dyserth's inner ward represents a great loss, the surviving outer ward and outworks are of national importance as the remains of a documented Royal castle with a very limited period of use that formed a precursor to the great campaign castle of his son Edward I. The remaining portions are likely to retain significant buried structural evidence and associated deposits with potential to enhance our knowledge of the construction, development and use of the castle and more widely of elite medieval military architecture and domestic practices in Wales and beyond. It may also retain artefactual evidence of material culture dateable to a closely documented period, along with environmental evidence of the use of the castle and its contemporary medieval landscape.

The scheduled are comprises the remains described and areas around them within which related evidence may be expected to survive.

Source: Cadw