St Clears Castle is an early 12th century earthwork motte and bailey fortress, founded by the Norman invaders. The castle stands in the junction of the Taf and Cynin rivers and was besieged, burnt and captured by various Welsh Princes, in 1153, 1189 and 1215. In the 13th century, William Marshall the Younger, earl of Pembroke, founded the stone castle, when adding a keep to the motte and encasing the bailey with a curtain wall. In the uprising of 1405, the castle surrendered to the forces of Owain Glyndwr and was then abandoned. Sadly no masonry remains, after the rectangular bailey was levelled, removing all the banks and ditches. 3 miles south is Laugharne Castle and 9 miles north-east is Carmarthen Castle.