St Quentin's Castle, Llanblethian (Cadw)

Probably built by English nobleman and military commander Gilbert de Clare in the early 14th century, the most notable remnants of this castle are its huge, twin-towered gatehouse and high stretch of curtain wall on the north of the site. In the centre of what was once a large fortress is an earthen mound with the remains of a thick-walled building on top of it, which may be all that’s left of an earlier keep.