Dolgellau appears to be the hub for the A49x series, with the A493, A494 and A496 all beginning within a three-mile stretch of the A470, which runs past the town. The reason is apparent: here, at the confluence of the Mawddach and Wnion rivers, is where the impenetrable mountain barrier gives way to steep sloping valleys.
Of these roads, it is the A496 that has the northernmost starting-point: a westbound turn from A470 at Llanelltyd marks the start of our route along the northern edge of the broad floodplain of the Afon Mawddach. The floodplain itself is low lying and marshy, which is why the A496 hugs the foot of the steep wooded hills to our right. On the far side of the tidal estuary, crossed only by an unclassified toll road running south from Pen-y-bryn, the largely parallel A493 sticks in similar fashion to the foot of the hills on the left bank of the river.
At Bontddu, we head inland through a wooded valley for a short distance before returning to the narrow coastal plain, which soon disappears altogether as we round the headland marking the southernmost point of the A496. As we do so, we see the Barmouth railway bridge running across the estuary, then we follow the road and railway into the town centre. Main roads in seaside towns do one of two things - either they run along the sea front, or, as in this case, they run at the back of town, sandwiching the town between itself and the coast.
As we continue north, we enter the Snowdonia National Park, the land to the right rising over many miles to the summit of Diffwys. We continue to hug the lower slopes of the hillside, with the coastal plain broadening out to our left. We pass through Dyffryn Ardudwy and other small villages as we progress northwards towards Llanbedr, where the coastal plain is sufficiently broad to allow the location of an airfield. From time to time we cross the end of wooded valleys draining the mountains to the east.
The next place is Llanfair, where we meet the railway and the coast once again, on the approach to Harlech. Paul Berry reports that in Harlech, you can find the steepest motorable road in Britain, though I understood this accolade was held by Rosedale Chimney in North Yorkshire. Harlech is also home to one of the most spectacular and well-preserved castles in the country, which dominates the town as much now as it must have done in the Middle Ages.
North of Harlech, the job of hugging the bottom of the hill is taken by the B4573 (the original route of the A496), leaving the A496 to find a very straight course across the coastal plain, past a wooded nature reserve (Morfa Harlech). Approaching Ynys, the road curves smoothly to the right over a new bridge opened in March 2013. Previously there was a sharp right over a narrow bridge. The older road and bridge survive, these days as a purely residential street. Having left Ynys we cross the level crossing before meeting the B4573 again, thus resuming our job as guardian of the base of the hills. The sea has now given way to a river estuary, this time the Afon Dwyryd. There is a toll road across, which links to the A487 at Penrhyndeudraeth. Until 2013 this crossed the single-track wooden Pont Briwet (which also carried the railway line). This has now been demolished and a new bridge is being built. The A496 continues north into a steep-sided gorge, which broadens out into the Vale of Ffestiniog. We meet the A487 at Maentwrog, crossing it and remaining south of the River Dwyryd towards our terminus on the A470 in the slate mining town of Blaenau Ffestiniog.
If it wasn't for the A470, I'd be describing a route leading all the way to the north Wales coast at Llandudno.
Having said that, the original northern terminus of the A496 was actually on the A487 at Maentwrog. It was extended to Blaenau Ffestiniog in the mid-1920s albeit entering town from the east rather than the west. In 1935 and also extended along the B4407 and A544 to reach Llandudno. When the A470 was extended, it terminated once again in Blaenau Ffestiniog.