BRITHDIR, a chapelry, in the parish of GELLYGAER, hundred of CAERPHILLY, county of GLAMORGAN, SOUTH WALES, 5 miles (S.E. by E.) from Merthyr-Tydvil, containing 792 inhabitants. This place, which is situated in a rich mineral district, has, within the last ten years, nearly doubled its population. This increase may be attributed to the establishment of the extensive ironworks on the estate of the Marquis of Bute, and to the collieries and other public works in the immediate vicinity, of which a more detailed account is given in the article on the parish of Gellygaer. The village is pleasantly situated on the banks of the river Romney, and the surrounding scenery, like that of the entire parish, combines numerous interesting features and a pleasing variety of picturesque and romantic beauty. The living is a perpetual curacy, annexed to the rectory of Gellygaer, in the archdeaconry and diocese of Llandaff. The chapel is a neat plain edifice, appropriately fitted up. At a short distance is a rude erect stone, about nine feet high, a monument of some remote period of antiquity, of which there are other remains in the vicinity.