Abercwmeiddaw Slate Quarry is located on the immediate north side of Upper Corris, on the hillside above the village. It opened in 1876 and comprised both open and underground workings. By 1882, 188 men were producing 4173 tons. The quarry produced hard slate slabs that were transported from the quarry via a tramway to the Corris Railway. At first material was lowerd by inclime to the mill, but as work developed material was brought out on the level by a locomotive worked tramway. When extraction deepened into a pit problems of uphaulage, rubbish disposal and pumping were solved by boring a tunnel from pit bottom to a point below the mill.
The remains are extensive. The constricted nature of the site required high retaining walls to contain tipping. Other features include machine-bored tunnels, the original tramroad formation, some small buildings (now in re-use), mill wheel pit, parts of the incline plane system, and some fine large-scale drystone walling.
The quarry closed in 1905 though some small-scale working has taken place since. The quarry was shown on Ordnance Survey County Series (Merioneth. XLII.8 1889) and was recorded during aerial reconnaissance by the RCAHMW on AP94-CS 1802-4 and AP945182/45, 49.
Sources:
A.J.Richards, A Gazeteer of the Welsh Slate Industry (1991), p.179-80
Association for Industrial Archaeology: A Guide to the Industrial Archaeology of Mid-Wales (1984).
David Leighton & Claire Parry, RCAHMW, 12 January 2015
