Beaumaris Castle on the Island of Anglesey is the great-unfinished masterpiece. It was built as one of the ’iron ring’ of North Wales’s castles by the English monarch Edward I, to stamp his authority on the Welsh but it was never finished. Money and supplies ran out before the fortifications reached their full height. Beaumaris is nonetheless an awesome site, regarded by many as the finest of all the great Edwardian castles in Wales.