FOREST, a hamlet, in the parish of MERTHYR-TYDVIL, partly within the limits of the new borough of that name, and partly in the hundred of CAERPHILLY, county of GLAMORGAN, SOUTH WALES, 5 miles (S. S. E.) from Merthyr-Tydvil. The population is included in the return for the parish. This hamlet forms a mountainous and partially wooded district between two branches of the river Tit at the western base of which runs the road from Cardiff to Merthyr-Tydvil, after crossing the bridge over the eastern or Bargoed Taf: a rail-road also passes from that town along the left bank of the Tif Vawr river, and, after crossing it, joins the canal opposite to the Quakers' Yard, in the parish of Gellygaer.