Slate quarry of uncertain date. Richards attributes it to the 1840s but according to Davies slate quarrying at Wernlas Deg began in the 1870s. Work had apparently been abandoned by the time of the 1891 OS. It comprises a linear quarry (520270) that may have led to an underground working, spoil tips (520271, 520273), shelter (520272) and small trial quarries (520274, 520275).
D.C. Davies, A Treatise on Slate & Slate Mining, 1878, p 46.
A.J. Richards, Gazeteer of Slate Quarrying in Wales, 2007, p 161.
Recorded as part of RCAHMW Uplands Initiative Project. R Hayman, H&H, 05/10/2011.