Quarry depicted on OS County series 3nd edition (Caernarvon. XXI.9 1916): history uncertain, area appears to fall within Nantle Vale quarry (Nprn400633) on earlier editions (1889, 1900).
Engine house, recorded as belonging to Ty Mawr E (Nprn275742), is portrayed in-use only on County series 1st ed. (1899).
(source: Lindsay 1974 (Hist. N Wales Slate Indust.), 326, 332)
RCAHMW AP945127/49-50
J.Wiles 16.06.04