Cyfanned Fawr Slate Works are associated with Cyfanned Fawr Lead and Copper Mine (NPRN 413822). The adit was driven in 1842, but when operations ceased pre-1887, the mine was working as a slate vein. On Ordnance Survey County Series maps dated 1889 (Merionethshire XXXVI,15) the site is described as a disused slate works (NPRN 413821). Remaining buildings and industrial works include shafts, masonry ore slides, a wheelpit, a roofless crusher house and settling pits.

Source: David Gwyn & Merfyn Williams (1996) `A Guide to the Industrial Archaeology of North West Wales?. Association for Industrial Archaeology

Claire Parry, RCAHMW, 25 November 2011.