WALWYN'S-CASTLE, a parish, in the union of HAVERFORDWEST, hundred of RHOS, county of PEMBROKE, SOUTH WALES, 6 miles (S. W. by W.) from Haverfordwest; containing 338 inhabitants. This parish, which. is situated near St. Bride's bay, is called by the Welsh Castell Gwalchmai, a name probably derived from the tradition that Gwalchmai, cousin of King Arthur, and a warrior of gigantic stature, having been driven from his inheritance in Galway, was wrecked off this coast, and interred here; and his remains are said to have been found in the reign of William die Conqueror. The rateable annual value amounts to £1011. 7. 5. The living is a rectory, rated in the king's books at £7. 13. 4., and in. the patronage of the Crown; present net income, £270, with a glebe-house. The church, dedicated to St. James, is an ancient edifice, not remarkable for any architectural details. Here is a Sunday school, in which about 30 males and females. are gratuitously taught. A tumulus near the church is supposed to mark the site of the ancient castle, but no particulars of its foundation or history are known: there are no vestiges of buildings of any kind, and the artificial mound may probably be only a sepulchral memorial raised over the remains of Gwalchmai, or some other chieftain.