Cwm Machno quarry is located to the south-west of Betws-y-coed, at the head of the valley of the Machno, a tributary of the Conwy river. It is a nineteenth-century slate quarry, a substantial undertaking working an open quarry on several levels as well as underground. Workings were connected by balanced inclines to water-powered mills area at village level. The quarry suffered from a lack of rubbish tipping space and there were also transport difficulties. Throughout its life road access only was available involving a long cartage to Trefriw, later Betws-y-coed, though there were proposals to connect to the Rhiwbach quarry by a tramway either on the surface or even via the latter's drainage tunnel. The quarry employed 70 men in 1872, 178 in 1898, and 108 in 1937-8. It finally closed in 1962.
Still visible (in 1991) are several inclines in a confusing pattern with newer works overlying older structures reflecting the constricted nature of the site. Also, several ruinous buildings which include mills and drumhouses, and some fine rubbish retaining revetments.

Sources:
D.Gwyn, Welsh Slate: the Archaeology and History of an Industry (RCAHMW 2015).
Ordnance Survey County series 25-inch map: sheet Caernarvon. XXIX.7, editions of 1889, 1900 & 1914.
A.J.Richards, A Gazeteer of the Welsh Slate Industry (1991), 71.

David Leighton, RCAHMW, 27 January 2015