The Ffestiniog Railway runs for 21 km from Porthmadog Harbour station up through the mountains to Blaenau Ffestiniog, climbing over 200 metres through some of the most dramatic scenery in Wales. It is the finest narrow-gauge heritage railway in Britain, and one of the oldest working railways in the world — the line was originally built in 1836 to carry slate from the quarries down to the port.
The journey takes about an hour each way. The trains are small and the track narrow (just under 60 cm gauge), which gives an intimacy with the landscape that you don't get on a standard-gauge line. The route passes through the Snowdonia foothills, along the shores of Llyn Mair, and up into the extraordinary landscape of Blaenau Ffestiniog itself — a town hemmed in by vast grey slate tips, an industrial landscape of strange, austere beauty.
Steam trains run most days in summer. The station at Porthmadog Harbour is a short walk from the town centre car parks. Allow a full day for the return trip if you want to explore Blaenau at the top — or combine with Portmeirion nearby.