Built in 1824 with two inclines which were removed in 1843. The Llanberis Lake railway is built on the track bed of part of the 4ft gauge Padarn Railway, which from 1843 to 1961 carried slates from Dinorwic Quarry, Llanberis, to Port Dinorwic on the Menai Strait. After the Padarn Railway closed the interal 1' 10.75" gauge quarry lines continued to be used until 1969 when the vast Dinorwic quarry finally closed. Several of the locomotives from the quarry were saved and in 1971 the Llanberis Lake Railway was born.
Dinorwic Quarry, the second largest producer, had a lot of similarities with Penrhyn. It was situated only a few miles away and used the same system of extraction using galleries. A tramway was first completed to Port Dinorwic (now Y Felinheli ) in 1824 and in 1842 it was replaced by the four foot gauge Padarn Railway. The two foot gauge wagons being loaded four at a time onto transporter wagons. Above the port they were unloaded and used a two foot gauge incline to access the quays . The port is active today as a yachting centre and the lock worked slate dock is still in use. At the quarry itself there were three main inclines A, B and C and the highest working level was over 1500 feet above sea level.
Part of the railway is now the Llanberris lake railway