Denbigh Castle is a dominating 13th century stone keep and bailey fortress, founded by Henry de Lacy. 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 great 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. 1 mile south is Llys Gwenllian Castle and 8 miles south-east is Ruthin Castle.