Built in 1073 by Robert of Rhuddlan above the River Clwyd, the mound would have been topped with timber fortifications, though it is possible that a stone structure was erected at a later date.
Adeiladwyd y domen gyntaf ym 1073 gan Robert o Ruddlan uwchlaw Afon Clwyd, a buasai amddiffynfeydd coed ar ei phen, er bod strwythur o gerrig wedi’i godi efallai’n ddiweddarach.