Dinas is a station on the narrow gauge Welsh Highland Railway, which was built in 1877 as the North Wales Narrow Gauge Railways Moel Tryfan Undertaking to carry dressed slate for trans-shipment to the LNWR. Passenger services ceased on 26 September 1936 until which time Dinas had been a joint station, known as Dinas Junction with the LNWR and later the LMS. In 1951, British Railways closed their part of the station but the line through the station remained open until the line from Caernarvon to Afon Wen was closed in 1964. The trackbed was subsequently developed as the Lôn Eifion tourist cycle route.

The Welsh Highland Railway is a 25-mile (40.2 km) long, restored 1 ft 11+1⁄2 in narrow gauge heritage railway in the Welsh county of Gwynedd, operating from Caernarfon to Porthmadog, and passing through a number of popular tourist destinations including Beddgelert and the Aberglaslyn Pass. At Porthmadog it connects with the Ffestiniog Railway and to the short Welsh Highland Heritage Railway. In Porthmadog it uses the United Kingdom's only mixed gauge flat rail crossing.