A considerable number of limekilns is situated on Carnau Gwynion, a series of limestone outcrops lying between the Nedd and Llia valleys. Three groups of these lie within a roughly rectangular enclosure numbered 1508 on the Ordnance Survey 1:2500 map of 1904. This enclosure was set aside as common land when the Great Forest Estate was sold by the Crown in 1830; it contains three distinct limestone outcrops.
D.J.Percival, RCAHMW, 1985.