Gorseddau Slate Quarry (NPRN 40557) was first opened in 1807, but its main period of working was between 1854 and 1857, when it was developed by the Bavarian mining engineer Henry Tobias Tschudy von Ulster. The visible remains include tiered workings and spoil tips set into a SW-facing hillside. It includes the remains of an incline, several ruined structures and a workers' village.
A block of 4 shelters, or 'gwaliau', located on a spoil tip (NPRN 532576). There are 2 in the centre oriented E-W, one adjoining to the N with an entrance on the W side, and another to the S with entrance on the E side. Each shelter is 4-5m square, with dry-built slate rubble walls standing up to 1.9m high, but with some collapse. The central shelters each retain part of a corbelled stone roof, and they are served by a cross-passage offset to the S.
Recorded as part of RCAHMW Uplands Initiative Project, W B Horton, H & H, 12/03/2013.