Caer'r Nant Stone Quarry is part of a network of quarries, spoil tips and tramways, including a tramway incline some 830 metres long (which connected the quarries with an iron and timber jetty), remains of a winding house and crushing plant. Modern quarrying started in Nant Gwrtheyrn shortly after 1850 to supply granite setts for paving and construction work in large cities. Three quarries were opened - Cae'r Nant, Porth y Nant (NPRN 40566) and Carreg y Llam (NPRN 40533). Ships were loaded regularly from purpose built jetties, carrying setts to Liverpool, Manchester and Birkenhead. In 1878, the settlement of Porth y Nant (NPRN 33025) was established for the quarry workers and their families.

B.A.Malaws, RCAHMW, 07 March 2006.