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 short inclined plane oriented SE-NW brought stone from a small quarry (nprn 527506) to the head of the main incline plane (nprn 527475). The incline measures 12m long and 3.5m wide and formerly spanned a tramway that ran beneath it (nprn 527487). The lower part is embanked and constructed with dry-built stone walls up to 1.5m high.
Recorded as part of RCAHMW Uplands Initiative Project, W B Horton, H&H, 19/12/2012.