The Cowlyd Tramway was a 2' narrow gauge railway line used to convey men and materials to Llyn Cowlyd Reservoir, near Trefriw in north Wales From the top of the Dolgarrog inclines, the line ran for some 4 miles largely parallel to, and to the north of, Afon Ddu to Llyn Cowlyd dam, where it ended in two sidings and a loop. Construction of the Tramway began in 1916, and reached Llyn Cowlyd the following year. It.closed "temporarily" in 1968 after a derailment of a workmen's train, but it never re-opened as it was deemed unsafe.