Tomen-y-rhodwydd is a mid 12th century earthwork motte and bailey fortress, founded by Owain Gwynedd. Built in 1149, the castle was taken and burnt in 1157 by Iorwerth Goch ap Maredudd of Powys, after which it was superseded by Tomen-y-faerdre. In 1212 during his campaign against Llywelyn ap Iorwerth, King John fortified the castle, which commands the eastern side of the Nant y Garth Pass. A dramatically ditched motte, stands on the north-eastern side of a ditched crescentic bailey, which is encased by an undulating bank. There are no visible traces of any buildings in the castle and to the south, its encasing continuous counterscarp bank is damaged by the road. 8 miles south is Castell Dinas Bran and 10 miles north-east is Caergwrle Castle.