Carreg Cennen Castle is One of the most spectacularly sited Welsh castles is Carreg Cennen, located north of Swansea, a few miles south-east of Llandeilo on a minor road off the A483. Spell-binding views are waiting to be experienced from the sharp hilltop upon which the castle sits There are few castles in Wales - or Europe for that matter - which can boast a more spectacular location than Carreg Cennen.  Its ruins crown a precipitous crag in a remote corner of the Brecon Beacons National Park.