|From:||Llanfair PG (SH530715)|
|Length:||24.6 miles (39.6 km)|
|Meets:||A5, B4419, B4421, B4422, A4080, A55, A5, B5112|
|Former Number(s):||B4420, B4423|
|Old route now:||A5|
|Route outline (key)|
The road starts on the A5 in Llanfair PG (generally marked on maps as Llanfair Pwllgwyngyll and on signs as Llanfairpwll, although the place name could well be much longer). Heading south, the road crosses the railway line and skirts the edge of the estate of Plas Newydd, now owned by the National Trust; the public entrance is on this road. After leaving that behind we wind into Brynsiencyn and zigzag through the village centre - there are a couple of sharp corners here.
After reaching open country once more there is a short multiplex with the B4419 and we appear to run along the Dwyran bypass; in fact the A4080 has always gone this way. There's a sharp bend to the left and we follow a dead-straight road southwest past the Anglesey Model Village into Pen-lôn where we reach an roundabout most unexpectedly. We turn right (left runs into the dunes of Newborough Warren) and soon reach Newborough, one of the few places on Anglesey where the name sounds English.
After leaving town we run through a wood and continue across the coastal marshes. Soon we cross the Afon Cefni and enter Malltraeth. A short distance further on the road bends round to the right, remembering the pre-1935 priorities here, and we TOTSO left and continue roughly southwards for about half a mile before a sharp right-hand bend takes us into Hermon. Continuing westwards, a dead-straight road takes us across the dunes to cross the Afon Ffraw to enter Aberffraw. The terrain becomes hillier as we head northwest to cut off a corner - although the road narrows on leaving the village.
At the top of the hill the road becomes S2 once more and the sea becomes visible ahead. We reach the west coast at Porth Trecastell, where there is a small car park, and then head north, turning slightly inland to reach the southern edge of Llanfaelog, where the road splits. We could continue straight ahead over the railway line into the village centre but let's turn left instead.
Continuing west, we cross another area of grassed sand dunes, with the sea to the left and Llyn Maelog to the right, and then enter Rhosneigr. By the clock tower in the village centre, with the sea visible ahead, we bend to the right and head north along Station Road; the sea often becomes visible to the left. On the northern edge of the village we bear sharply right and skirt a golf course before a few more bends take us to a low bridge under the railway line; the station is still open. We then follow a winding road southeastwards back to Llanfaelog to a T-junction opposite the church, which is where we would have ended up if we'd continued ahead in the last paragraph.
We turn left and head northeastwards out of town. There are a few more miles of open country, with the sea now left behind in Rhosneigr. Presently we reach a dumbbell interchange which is A55 J5. A few hundred yards further on we return to the A5 at a crossroads and the A4080 ends. Ahead is the B5112.
The A4080 came into being in 1935 as a single Class I road around the southern side of Anglesey, mirroring the A5025 round the north which dates to a few years earlier. The road was cobbled together out of a number of previously existing roads of lesser status.
The B4420 started on the A5 in Llanfair PG and headed southwest, originally to Newborough but was soon extended across the Cefni to end at Bethel. The A4080 followed this to its crossing of the Cefni then detoured via Hermon, following a previously unclassified road along the coast (and ignoring the B4422 which ran alongside the railway line which was declassified instead). This took the road to Llanfaelog, after which it followed the B4423 back to the A5 at Engedi. The loop to the west, to Rhosneigr, existed from the beginning, although it seems that when the A4080 was first classified the road immediately south of Llanfaelog cutting off the corner remained unclassified.
In 1980 the Britannia Bridge was reconstructed to carry vehicular traffic across the Menai Strait; it was given the A5 number and the A4080 was extended east along the old route of that road into Menai Bridge and across the actual bridge of that name to end on the A5122 on the mainland. When the A55 was extended across Anglesey in 2001 the A5 was given its old route back and so the A4080 was cut back to start once again on the A5 in Llanfair PG.