Barmouth   Barmouth originated as a fishing port and the fishing industry, especially shellfish, is still important to the town. During the 18th and 19th centuries Barmouth and the Afon Mawddach developed to become a major ship building centre. Due to the rail link, Barmouth became a classic seaside resort during the 19th century. Barmouth Bridge, the half mile railway viaduct spanning the Mawddach Estuary is over 125 years old and the only operational wooden viaduct remaining in Wales. On the open hillside behind Old Barmouth is Dinas Oleu (Fortress of Light), the first property given to the National Trust on 29 March 1895. The 4.5 acre site has been added to, with 12 acres of cliffland to the east purchased in 1980, and 0.5 acres of steep grassy bank added to the west in 1986.