The Penrhyn Quarry Railway was a narrow gauge railway in Caernarfonshire (now Gwynedd), Wales. It served the Penrhyn quarry near Bethesda, taking their slate produce to Port Penrhyn, near Bangor. The railway was around six miles (9.7 km) long and used a gauge of 1 ft 10+3⁄4 in (578 mm). The railway opened in June 1801 and was one of the earliest overground narrow gauge railways in the world. It closed on 24 July 1962, the track being lifted in 1965 and sold to the Ffestiniog Railway.