Aberystwyth
Aberystwyth stands on the coast of Cardigan Bay, where the Ystwyth and Rheidol reach the sea. Its castle was built for Edward I as part of the English conquest of Wales, overlooking a harbour and the town beside it. The walls became a focus of later Welsh resistance. In 1404 Owain Glyndŵr's forces captured the castle during his uprising against English rule. They held it until 1408, when English forces retook it. The fortress survived into the Civil War, but was ordered dismantled in 1649. Its ruins on the headland recall both royal power and the Welsh revolt that challenged it.