The Porthmadog cross town link is a section of the 1 ft 11 1⁄2 in (597 mm) narrow gauge Welsh Highland Railway, specifically built to link with the Ffestiniog Railway in Porthmadog, and runs along partly what was called the Junction Railway, previously existing as part of the original Welsh Highland Railway. This had been removed some time after that railway closed in 1936.
It has been built using the new powers obtained by the Ffestiniog Railway and runs from Harbour station on the Ffestiniog Railway to Pen-y-Mount Junction close to Pen-y-Mount on the Welsh Highland Heritage Railway.
The route is as follows:
For reference, the Junction Railway was empowered to run:
The line reopened on 8 January 2011, linking the Ffestiniog Railway with the Croesor Tramway allowing passenger trains to run between Caernarfon and Blaenau Ffestiniog.
Coordinates: 52°55′27″N 4°07′35″W / 52.9242°N 4.1263°W