Glyn Pits is a colliery that was sunk by Capel Hanbury Leigh to provide for his Pontypool Iron and Tinplate works. The two fine engine houses, both contain their engines. The older engine house, dating from 1845 date, has an integral lattice ironwork supporting the beam engine, both being designs of the Neath Abbey Ironworks.

There are substantial pumping and winding remains - flywheel, crankshaft, gearing, sheaves and pump-rods. On the opposite (eastern) side of the two masonry-lined shafts, with a T-bob, pump-rods and fan drift is the later engine-house. This huge structure contains a, possibly second - hand vertical engine of unknown manufacture, dated 1859-65 by RCAHMW. The winding sheaves and some of the brake mechanism remain, as do wire ropes. The boiler-water reservoir is at the rear of the site. At Upper Race ST 285984 there is a vast hushing, with easily traceable water-channels and ponds above. There is a one mile long water feeder from Blaen-Bran ponds at ST 267972.

Claire Parry, RCAHMW, 25 July 2011

Source: A Guide to the Industrial Archaeology of South East Wales, AIA, 2003