Porthmadog, a small coastal town and community in the Eifionydd area of Gwynedd, came into existence after William Madocks built a sea wall, the Cob, in 1810 to reclaim a large proportion of Traeth Mawr from the sea for agricultural use. The diversion of the Afon Glaslyn caused it to scour out a new natural harbour which had a deep enough draught for small ocean-going sailing ships. The first public wharves were built in 1825. Individual quarry companies followed, building a series of wharves along the shore almost as far as Borth-y-Gest, and slate was carted from Ffestiniog down to the quays along the Afon Dwyryd, then boated to Porthmadog for transfer to seagoing vessels. A number of shipbuilders were active, and were particularly well known for the three-masted schooners known as Western Ocean Yachts, the last of which was built in 1913.
Porthmadog's role as a commercial port, already reduced by the opening of the Aberystwyth and Welsh Coast Railway in 1867, was effectively ended by the First World War, when the lucrative German market for slate disappeared. The nineteenth century wharves still survive, but the slate warehouses have been replaced by holiday apartments, and the harbour is used by leisure yachts.
Source: https://en.wikipedia.org/wiki/Porthmadog£History

RCAHMW, 9 August 2017