The Penmaenmawr Granite Quarry is an extensive one that is still operational. The quarry was formed from an amalgamation of several workings originally dating from 1830. Some of the counterbalance incline systems remained in use until 1967, and with the Pencoed storage bins and clock face in the Graiglwyd workings, they can be seen from the main road. The stone was originally quarried for setts, although from 1896 the quarries produced crushed roadstone and railway ballast. There was little sett making after the 1930s. The damaged structure of the Penmaen crushing mill, or Bonc Jolly, dates from 1893 and it consists of a series of stone or brick bases. There are also remaining drum houses and dressing sheds.

Source: David Gwyn & Merfyn Williams (1996) `A Guide to the Industrial Archaeology of North West Wales?. Association for Industrial Archaeology

RCAHMW, 14 November 2011.