Westminster Colliery was sunk in the Moss Valley in the mid-nineteenth century, although mining activity in the area is believed to date from at least the eighteenth century. It developed into a substantial site and map evidence suggests there were six shafts, although some were disused by the time of closure of the colliery in 1925. The site was demolished and cleared by 1939. The colliery was associated with Gwersyllt Colliery (nprn 413947).
B.A.Malaws, RCAHMW, 05 February 2009.