Garnddyrys Ironworks (nprn 34137) was in operation c1817-1861. The forge was probably mainly concerned with puddling, and had an associated rolling mill powered by water. Although puddling furnaces have been recorded here (nprn 91627), no evidence of such structures was found. The layout of the forge is uncertain, but it is likely that a waterwheel stood in the centre, fed by a head race from the upper pond immediately to the E (nprn 91628), driving the mils. One group of 4 sheared holding down bolts (probably for a bearing) is visible above ground. Otherwise the ground surface is undulating grass with some stone and brick rubble, over an area approximately 80m NE-SW by 30m.
R Hayman, Hayman & Horton, 26/11/2003