The Groes Fawr Valley lies in the upland area of Bleancaron, in the upper Teifi valley. It is situated 5kn east of Tregaron, and falls within the parish boundaries of Caron-is-Clawdd. The area was surveyed c. 1989-1991 by (or in collaboration with) Dyfed Archaeological Trust, seemingly as part of a Cadw Uplands Initaitive.
Source: Archaeological Survey Report on Groes Fawr Valley (GFV)
L. Moore, RCAHMW, 12th April 2012