Denbigh Castle is a dominating late 13th century stone keep and bailey fortress, founded by Henry de Lacy, earl of Lincoln. This Edwardian hilltop castle was built in two phases, replacing a Welsh royal residence, of the princes of Gwynedd. On the town side, the curtain wall of the oval bailey is flanked by large octagonal towers and a spectacular four storey triple towered Great Gatehouse. To the south and west, are earlier semi-circular towers plus a concentric mantlet and a postern gate and barbican, which has a complex series of gates, passages and drawbridges. To the north and erected simultaneously with the castle are the medieval town walls, flanked by two twin towered gatehouses and four other towers. A mile south is Llys Gwenllian and 8 miles south-east is Ruthin Castle.