or RHYDDLAN, a parliamentary borough of N. Wales, county of Flint, on the Clwyd, which is here crossed by two bridges, 3 miles N.N.W. of St Asaph. It was once a large and important place, but is now distinguished for little except its ancient remains; it contains only a few streets, but is generally well built, and has several places of worship belonging to Wesleyan and Calvinistic Methodists, Baptists, and Independents. The castle of Rhuddlan is a square red stone edifice, with six massive round towers, and has little pretensions to architectural elegance. Its age is not certainly known, but it was in existence in the eleventh century, and was attacked and burned by King Harold in 1063. In after-times it was a place of much importance and the scene of many historical events. Of the house where Edward I. held in 1283 the Parliament which secured the Welsh rights a portion still remains, and is marked by an appropriate inscription. It was in Rhuddlan that the infant son of Edward I. was acknowledged Prince of Wales. In the civil war the castle was held by the royalists, but was taken by General Mytton in 1646; and soon after dismantled. The River Clwyd is navigable as far as Rhuddlan for vessels of 60 tons. Pop. (1851) of the borough, 1472; of the parish, 3049.