In 1868, the parish of Penllyn contained the following places:
"PENLLYN, a parish in the hundred of Ogmore, county Glamorgan, 1 mile N.W. of Cowbridge, its post town, and 5 miles from Bridgend. The village, which is of small extent, is wholly agricultural. In the neighbourhood are the ruins of St. Donat's Castle, built by Sir W. Stradling, whose family occupied it for six centuries. The gateway is carved with curious medallion circles. The portion of the building which is still inhabited is situated on a hill, and commands a view over the Channel. The living is a curacy annexed to the vicarage of Llanfrinach, in the diocese of Llandaff. The church, dedicated to St. Brynach, is an ancient structure, situated in a wooded dingle, which runs down to the shore. The church contains the mortuary chapel of the Stradlings, to which family it has panel paintings of the 16th century; also a tomb to Sir Thomas Stradling, the last of his race, bearing date 1738. The churchyard contains a cross."