The Bethesda branch line was a 4 1⁄4-mile (6.8 km) branch of the North Wales Coast Line between Bangor and Bethesda in Gwynedd, North Wales. Permission was granted by an Act of Parliament in August 1880 to construct the line, which was opened in July 1884. As well as the terminus station there were stations constructed at Felin Hen (downgraded to a halt from 1939) and Tregarth. Regular passenger services ended in 1951 whilst goods and public excursion journeys kept the line going until its final closure in July 1962.
Although the tracks have been lifted and there are little left of the stations there are still a number of features of the line still very much intact. These include the viaduct over the Afon Cegin which is now listed, the 279 yd (255 m) brick and slate lined Tregarth Tunnel and a bridge over the Afon Ogwen.