|Operational No.||UB 20.87|
|Stations | Locations | Bridges | Tunnels | Map|
Pont Seiont, is the first major bridge crossing on the route out of Caernarfon. It lies near the roundabout at the end of St Helens's Road.
Designed by C. E. Spooner about 1867, it is a two-span brick river bridge over the Afon Seiont, which flows from Snowdon’s northern slopes.