This article is taken from an original from the main wikipedia, and suitably modified for presentation here. Click here for the original, expanded article
The A470 is a major long-distance connective spine road in Wales, running from Cardiff on the south coast to Llandudno on the north coast. It covers approximately 186 miles (299km), over a zig-zagging route through the entirety of the country's mountainous central region, including the Brecon Beacons and much of Snowdonia National Park.
In this area it is a primary trunk route throughout its length, albeit 'single carriageway of variable quality (and even in brief instances single track) in order to accommodate the landscape. It takes in several town centres, right-angle (or tighter) divergent junctions and sharp curves.
Route in detail in the FR Area
Most of the route north of Brecon consists of older routes now renamed 'A470'.
The country becomes more forested and the road climbs up through Dinas Mawddwy and then steeply up the eastern foot-hills of Cadair Idris before dropping down through tortuous bends to the Dolgellau by-pass. More sharp twists and turns in the forestry and through the village of Ganllwyd brings the road up onto the high plateau of the Cambrian dome where the road runs roughly parallel to, but some distance away from, the ancient track of Sarn Helen Roman road passing the redundant nuclear power station of Trawsfynydd. A right turn beyond the power station takes the road on to Ffestiniog and Blaenau Ffestiniog before heading over the Crimea Pass to Dolwyddelan. A sharp left turn interrupts the A470 as it becomes the A5 for a short distance towards Betws-y-Coed before turning right again back onto the A470 just before Waterloo Bridge, Betws-y-Coed.
The road is mountainous in parts, particularly over the Brecon Beacons, south of Dolgellau and over the Crimea Pass.