ABERCASTLE, a village in Mathry parish, Pem broke; on the coast, 6½ miles NNE of St. David's. It has a small harbour, frequented by coasters. On the farm of Longhouse, above it, is a cromlech, comprising a massive capstone 16 feet long, four supporting stones 5½ feet high, and two other stones.

(John Marius Wilson, Imperial Gazetteer of England and Wales (1870-72))