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Location Map ( geo)
Cameraicon.png View gallery (109)
From:  Cardiff (ST191746)
To:  Llandudno (SH786822)
Distance:  185.1 miles (297.9 km)
Meets:  A4119, A4160, A4161, A48, A469, M4, A4054, B4262, A468, A473, A4058, A4223, B4275, A472, A4059, A4060, A4102, A465, A4215, A40, B4601, B4602, A438, A479, B4350, B4594, A483, B4358, A4081, A44, B4518, A489, B4569, B4568, B4518, A489, A458, A487, B4416, A494, A493, A496, A4212, B4391, A5, B5427, B5106, A548, B5279, A547, B5381, A55, B5115, A546
Former Number(s):  A438, A4073, A479, A44, A492, A489, A4084, A458, A487, A4108, A496
Old route now:  A4054
Primary Destinations
Highway Authorities

Cardiff • Conwy • Welsh Government

North & Mid Wales TRA • South Wales TRA
Traditional Counties

Brecknockshire • Caernarfonshire • Denbighshire • Glamorgan • Merionethshire • Montgomeryshire • Radnorshire

Route outline (key)
A470 Cardiff Bay – Gabalfa
A470 Gabalfa – Brecon
(A40) Brecon Bypass
A470 Brecon - Llandudno


The A470 is a very important route for traffic through Wales, from the south to the north coast, having mostly being created by renumbering trunk roads that originally had other numbers. Its original route was from the present Cardiff Bay as far as the A40 in Brecon and it was only comparatively recently that it was extended (in stages) to Llandudno. The majority of the route forms the Cardiff to Glan Conwy Trunk Road.

Section 1: Cardiff Bay – Coryton

Lloyd George Avenue

The A470 starts on a large roundabout / small gyratory completely encircling Craft in the Bay, next to the Wales Millennium Centre in Cardiff Bay. It then heads up Lloyd George Avenue, a much-improved version of the former Collingdon Road. This is a D2 with all too many signalized intersections, supposedly in imitation of a continental boulevard. At the first of these intersections, next to Cardiff Bay station, the A4234 diverges along Hemingway Road, offering a much faster route into Cardiff city centre.

Lloyd George Avenue comes to a crashing halt at Herbert Street, which may be the A4160, at yet another signalized intersection. The path forward is blocked by the South Wales Main Line. We might be multiplexing with the A4160 as we turn left into Herbert Street to pass under the Cardiff Bay branch that we have been closely paralleling so far, then we turn right at a crossroads with yet more traffic signals onto Bute Street (however much the signage tries to hide this).

As we pass under the South Wales Main Line, we are finally on the historic A470, but not for long. At the next crossroads, the original route ahead into Hayes Bridge Road is a strange mix of pedestrianization and heavy construction traffic, so we turn right into Bute Terrace. We encounter our umpteenth signalized intersection at Churchill Way, a spacious dual carriageway to nowhere, concealing the docks feeder, rather than any exciting roads scheme. Then we pass once again under the lines into Cardiff Queen Street.

At the next T-junction, with obligatory traffic signals, we are rejoined by the A4234, which would have been a much faster route to here from the Bay. Then, at the following crossroads (guess), with the charming surroundings of the gaol and fire station, we TOTSO left into Fitzalan Place. At the far end of Fitzalan Place, we reach the A4161 Newport Road at yet another signalized crossroads. Ahead is an unclassified road to the A469 in Roath that would let us rejoin the A470 in Gabalfa, but instead we turn west to multiplex with the A4161.

This multiplex passes back under the Valley Lines, then bears sharp right and sharp left in an obvious by-pass of the pedestrianized area. After failing to turn right at another short-cut, Park Place (signalized crossroads, signposted Civic Centre), then passing through the Gorsedd Gardens in front of the National Museum and City Hall, we finally regain our identity at the north-east corner of Cardiff Castle. Here, the A4161 turns along the east and south sides of the castle, but we instead turn right up the North Road, passing along the side of City Hall. It provides a broad thoroughfare along the west side of Cardiff Civic Centre, where you will find the University of Wales, The Welsh Office, the National Museum of Wales and other grand looking buildings. We continue north through a single 3-lane carriageway running a tidal flow system, which has been there for as long as I can remember – at least 25 years. The road then passes over the top level of a three level stacked roundabout junction with the present alignment of the A48 before bearing left, on dual carriageway towards the M4, at junction 32. Here, we pass through another three-level-stacked roundabout – this one being one of the largest, if not the largest, roundabouts in the UK. It's so big, we pass under the first section of circulatory carriageway, then under the M4, then eventually over the other side of the circulatory carriageway. On the hill to the right you can see a fairytale castle – Castell Coch (The Red Castle) – built as a folly by the Marquis of Bute.

Section 2: Coryton – Rhayader

The A470 dual carriageway near Taff's Well

We continue north, following the Taff Valley towards Pontypridd and Merthyr Tydfil - still dual carriageway. Running parallel in the valley is the A4054; this was once the A470. A left turn at Pontypridd takes you to the most famous of Welsh Valleys, the Rhondda, but we carry on north towards Abercynon and Mountain Ash. The A470 through this section is beautifully engineered through the valley, including split-level sections and full grade separation and hard shoulders, built during the 1970s. The first roundabout we meet is with the A4059 to Mountain Ash and Aberdare.

Another roundabout, this time with the A4060, signals the start of the Merthyr Bypass, the most recent section of the A470 dual carriageway to open, in two parts during 1996 and 1997. This section is not grade separated: two roundabouts give access into Merthyr Tydfil and its retail parks. The final roundabout is with the A465; ironically, before the bypass, the A470 was grade separated from the A465 at a junction just to the east of this point. The road continues beyond the roundabout as single carriageway, rejoining the old alignment about a mile beyond.

The A470 through the Brecon Beacons

We now head across the Beacons to Brecon. High in the mountains we meet the A4059 from Hirwaun, to the south west. We run along open moorland, largely devoid of trees, but plenty of sheep! We pass Storey Arms, the traditional start of the footpath to South Wales' highest point (Pen y Fan) then the road descends to a roundabout on the A40 at Brecon. We pass to the south of Brecon, on a dual carriageway multiplex with the A40 (the second - and final - time the A470 disappears), then we turn left at the next roundabout, resuming our identity as the A470. This next stretch was once part of the A438. At the next significant junction after leaving Brecon behind, the A470 TOTSOs left towards Llyswen – the road straight on is the A438 towards Hereford.

After three miles we reach another T junction, where the A470 turns left again. The right turn here is the A479, heading south again and this next section of the A470 was also part of the A479. We've now reached a section of the A470 that I'm not familiar with. The map suggests that we are in the Wye valley, which we follow for around 12 miles until we reach Builth Wells, where we meet another north-south route, the A483. After crossing the River Wye (and the A483) at Builth, we leave the River Wye for a short time before returning to the river valley as we make our way to Rhayader on the A44.

Section 3: Rhayader – Dolgellau

Near Llanbrynmair

To the west of Rhayader are the Elan Valley reservoirs, which provide water to the West Midlands. We remain in the Wye Valley, heading north-west along a multiplex with the A44, where the A470 takes priority. Just to the south of Llangurig we say goodbye to the A44 and the River Wye, as we head north east towards Llanidloes, crossing the watershed into the Severn Valley, then on to a junction with the A489 to Newtown, where we find ourselves just 6 miles from the A483 again. At this junction we turn left, heading north west towards, but not quite reaching, Machynlleth. 6 miles short of Machynlleth, we reach the A489, where once again we turn right to stay on our route. We skirt the edge of Dyfi Forest and meet the A458 (from quite a bit of the English Midlands) at a roundabout. We curve round to the west now, towards Dolgellau and Cadair Idris, where we meet the A487 (which did pass through Machynlleth!).

A quick clarification of the A470's route from Glantwymyn (Cemmaes Road) to Dolgellau. Following the right turn at Cemmaes Road (the turning 6 miles short of Machynlleth) the A470 continues through various small villages until it reaches a roundabout at Mallwyd, where the A458 ends, and the A470 continues straight on through the village of Dinas Mawddwy and on into the mountains. To get to Dolgellau the road has to climb over a mountain through the Bwlch yr Oerddrws pass, a pretty steep incline that can cause a few cars to overheat. The road then drops down more gradually to meet up with the A487 at Cross Foxes (the A470 continues straight on here to Dolgellau, no left turns needed, the A487 is the subservient road here).

Dolgellau has a bypass now but before this the queues to get through here were horrendous. The streets were too narrow to cope with the traffic, and what is actually a pleasant town was marred by the volume of queuing traffic on the road. There are two left turns here. The A493 follows the south bank of the Mawddach Estuary and the A496 stays on the north bank towards Barmouth and Harlech.

Section 4: Dolgellau – Llandudno

The A470 continues north on its multiplex with the A487 through Coed y Brenin Forest Park. We eventually reach Trawsfynydd, home of a former Nuclear Power Station. What on earth was that doing in the National Park? The A4212 runs east to Bala on the A494, whereas three miles north of Trawsfynydd, we reach the end of our multiplex with the A487. Our road turns off to the right towards Ffestiniog and Blaenau Ffestiniog whereas the A487 heads off towards Porthmadog.

A silhouette view at sunset from the A470 south of Betws-y-coed

The fact that the Snowdonia National Park excludes Blaenau Ffestiniog should tell you as much as you need to know about this slate town. The slate caverns nearby are worth a visit, though.

The A470 at Llanrwst

We continue north through more forest and mountain scenery, until we cross the River Conwy immediately before reaching a T junction with the A5 to the south east of Betws-y-coed. A few yards further north on the A5, the A470 turns off again, heading down the Conwy Valley on the last lap of our journey, towards Llanrwst and then to a junction with the A55 just to the east of the Conwy tunnel. From here it is a short hop across loads of roundabouts and a one-way loop to our journey's end at the seafront (the A546) in Llandudno.


The original 1922-23 route was from Cardiff Docks to A40 at Brecon (at the now named Tarell roundabout). It was extended northwards to Glan Conwy in 1972 (per the Cymru : Wales 1972 Report).

Cardiff Docks

A470 formerly terminated at Pier Head

The original southern termination point was slightly more south than it's current location. A470 followed Bute Street to finish where Stuart Street joins, by Pier Head (Tacoma Square is more recent).

Opening Dates

6 October 1959 - Whitchurch Bypass (Cardiff)

21 October 1964 - Trawsfynydd Bypass (opened as A487)

3 December 1971 - Tongwynlais - Nantgarw

29 June 1973 - Nantgarw to Upper Boat

18 December 1973 - Upper Boat to Abercynon

28 August 1980 - Brecon Bypass section

13 April 1981 - Dolgellau Bypass

4 November 1985 - Abercynon to Pentrebach

18 December 1985 - Llandudno Link Road (from A55)

May 1988 - Minffordd to Dolwyddelan

25 February 1991 - Llanidloes By-Pass

8 November 1996 - Pentrebach to Cefn Coed (Section 1)

18 July 1997 - Pentrebach to Cefn Coed (Section 2)

October 1997 - Cancoed to Minffordd (Lledr Valley Stage 1)


BBC News

Roads UK

Related Pictures
View gallery (109)
A470 Level Crossing - Coppermine - 23685.jpgA470 Viaduct - Merthyr - Coppermine - 15956.jpgA470 South of Betws.JPGThe A470 south of Trawsfynydd - Geograph - 1574658.jpgA470 - Geograph - 601199.jpg
Other nearby roads
Merthyr Tydfil
A40 • A438 • A4059 • A4062 (Brecon) • B4520 • B4557 (Brecon) • B4558 • B4559 • B4601 • B4602 • Ffordd Cambria • NCN8 • T75 (Britain) • T77 (Britain)
A400 • A401 • A402 • A403 • A404 • A405 • A406 • A407 • A408 • A409 • A410 • A411 • A412 • A413 • A414 • A415 • A416 • A417 • A418 • A419
A420 • A421 • A422 • A423 • A424 • A425 • A426 • A427 • A428 • A429 • A430 • A431 • A432 • A433 • A434 • A435 • A436 • A437 • A438 • A439
A440 • A441 • A442 • A443 • A444 • A445 • A446 • A447 • A448 • A449 • A450 • A451 • A452 • A453 • A454 • A455 • A456 • A457 • A458 • A459
A460 • A461 • A462 • A463 • A464 • A465 • A466 • A467 • A468 • A469 • A470 • A471 • A472 • A473 • A474 • A475 • A476 • A477 • A478 • A479(W) • A479(E)
A480 • A481 • A482 • A483 • A484 • A485 • A486 • A487 • A488 • A489 • A490 • A491 • A492 • A493 • A494 • A495 • A496 • A497 • A498 • A499
Defunct Itineraries & Motorways: A403 • A404(M) • A405 • A407 • A423(M) • A430 • A437 • A446(M) • A455 • A464 • A475 • A491

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