TREVOR-TRAIAN, a chapelry, in the parish of LLANGOLLEN, union of CORWEN, Nanthewdy division of the hundred of CHIRK, county of DENBIGH, NORTH WALES, 3 miles (E.) from Llangollen, on the road to Wrexham: the population, though formerly returned separately, is now included in the return for Llangollen-Traian, with which it jointly forms one of the principal divisions of the parish. This chapelry comprises the mountainous range to the north of the town and the river Dee; and contains the ruins of Castell Dines Brin, an historical notice of which is given in the article on Llangollen. It abounds with very extensive rocks of limestone and other formations; and the navigable feeder of the Ellesmere and Chester canal passes within its southern boundary, along the northern bank of the river Dee, extending from the main branch near the north end of the Pont-y-Cyssylltau aqueduct, to its junction with the same river, at a short distance below the church of Llantysilio. The rateable annual value of the township has been returned at £9197. The living is a perpetual curacy, endowed with £400 private benefaction, £600 royal bounty, and £800 parliamentary grant; net income, #87; the patronage and impropriation belong to the Misses Thomas. The chapel is a small plain edifice, built by John Lloyd, Esq., of Trevor Hall, in 1742, for the use of his family, but not consecrated until 1772. The chapelry shares with Llangollen-Traian in the produce of several small bequests for the instruction of children, and for the relief of its poorer inhabitants. The remains of Castell Dinas Bran, situated on the summit of a conical isolated hill, rising to a considerable height out of the vale, and very steep, extend about one hundred and ninety feet in length, and one hundred and fifty in breadth, having on one side a deep trench cut in the solid rock. To the north of them is Craig-Eglwyseg, exhibiting for the distance of half a mile a vast assemblage of rocks composed of different tiers, like an immense flight of steps. Near Trevor Hall is a very interesting natural cavern, extending into a limestone rock to an unknown distance under the range of Trevor hills, and adorned by a great variety of very beautiful specimens of stalactite; in it have been found fossil remains of the hyena and of animals of the antediluvian world.