There was a small brickworks complex operational before 1900 at Porthwen, but only the main quarry and inclines are pre-1900. The site fell out of use in 1900 but was in use again by 1924 when the present buildings were completed. The works were disused by 1949 and the tramway removed. The surviving remains includes a quarry, incline system, processing works, two tall square plan chimneys, brickworks, beehive kilns and harbour.

Sources:
Site File AN/IND/SH49, from notes by A.J. Parkinson
David Gwyn & Merfyn Williams (1996) `A Guide to the Industrial Archaeology of North West Wales?. Association for Industrial Archaeology

J Hill, RCAHMW, 1 March 2004