This is the easternmost of the many cliff forts to be found on the Gower Peninsular.
Coflein (J. Wiles, 2002) has this brief description:
A level area of promontory, c.55m by 30m, is cut off to the W by two lines of defences, the outer, said to follow a modern field boundary, barely tracable, the inner being a bank and ditch.