Pont Cyfyng slate mill is located on the west bank of the Afon Llugwy, below a minor road, about 1.5 km south-east of Capel Curig. It is an example of a 'remote mill' situated some distance from the slate working area, in this case Foel (Moel Siabod) Quarry (NPRN 400563) some 2.4 km to the south-west. Material was carried to the mill by a series of inclines, at one time passing beneath the road, to the mill. The mill is not portrayed as such on early Ordnance Survey mapping, and it may only have had a short life during the 1860s when it had sandsaws, possibly later replaced by circular saws. The mill is now a ruin, though outlined on modern large-scale mapping. There are (in 1991) massive slate bases for what appear to be reciprocating saws, and a pit for a breast shot wheel.
Sources:
OS County Series 25-inch map: sheet Caernarvonshire XVIII.14, edition of 1889.
D.Gwyn, Welsh Slate: the Archaeology and History of an Industry (RCAHMW 2015), p.108-9.
A.J.Richards, A Gazeteer of the Welsh Slate Industry (1991), p.72.

David Leighton, RCAHMW, 17 June 2015