The Chepstow Castle ruins in Monmouthshire, Wales, on top of cliffs overlooking the River Wye, is the oldest surviving post-Roman stone fortification in Britain. Its construction was begun under the instruction of the Norman Lord William Fttzosbern, soon made Earl of Hereford, from 1067, and it was the southernmost of a chain of castles built along the English-Welsh border in the Welsh Marches.
Corfe Castle, Dorset, UK ~ The castle stands above the village and dates back in some form to the 10th century. It was the site of the murder of Edward the Martyr in 978. During the English Civil War it was a Royalist stronghold and was besieged twice, in 1643 and again in 1646. It is currently owned by the National Trust and is open to the public.