Minllyn is a slate and slab quarry (nprn 310049) begun in the C19, the most productive phase of which began after the Carlyle Slate & Slab Company was formed in 1872. Work ceased in 1924. A cast iron pipe approximately 0.18m diameter, half-buried, is 250m long NNW-SSE from a reservoir (nprn 527530) down a steep hill towards engine and boiler house (NPRN527466). It probably carried water for the boiler, although it could also have fed a Pelton wheel.
A.J. Richards, Gazetteer of Slate Quarrying in Wales, 2007, p 250.
Recorded as part of RCAHMW Uplands Initiative Project, W B Horton, H&H, 17/12/2012.