Carreg Cennen Castle in Carmarthenshire

You're standing at Carreg Cennen Castle, or Castell Carreg Cennen in Welsh. The name roughly means castle on a rock by the Cennen, the river you can see winding through the valley below. Look over to the south side. The wall there sits right on the edge of a limestone cliff more than ninety metres high. In the Middle Ages, you couldn't ask for much better protection.