A road over the top of the Cambrian Mountains
The Cwmystwyth road links the Ystwyth valley in Ceredigion with the Elan Valley in Powys, and there is not much else like it in Wales. The classified part is the B4574, six miles (9.7 km) between Pont-rhyd-y-groes and Devil’s Bridge through the upper Ystwyth valley; east of the hamlet of Cwmystwyth the road narrows to a single track and climbs over the watershed towards Pont ar Elan and the Elan reservoirs. The AA once named the Rhayader-to-Devil’s-Bridge run one of the ten most scenic drives in the world, and Visit Mid Wales still quotes the claim.
From Machynlleth the usual approach is south on the A487 to Aberystwyth and then inland, or east on the A44 through Ponterwyd; Devil’s Bridge is about 26 miles from town, roughly 39 minutes’ driving. Set a day aside for it rather than treating it as a way of getting somewhere.
The largest metal-mining landscape in Wales
Above Cwmystwyth the hillside opens into something that stops most passengers mid-sentence: several hundred acres of grey spoil, open trenches, ruined buildings and water channels up the northern slope of the Ystwyth. Natural Resources Wales puts the site at around 250 hectares, worked on three lodes. Cadw’s schedule entry — Copa Hill/Cwmystwyth Lead, Copper and Zinc Mines, reference 752, scheduled on 5 June 1985 — lists shafts and adits, opencast workings, water-management and transport systems, dressing floors, offices, houses, garden plots and even an early twentieth-century tennis court. Four separate mines were worked here: Pugh’s, Kingside, Penguelan and Copa Hill.
Sources differ on when it stopped: Cadw runs the working life from the Bronze Age, roughly 2300 to 800 BC, through to 1939, while Natural Resources Wales’s case study says the mine was finally abandoned in 1950. In October 2002 the Banc Ty’nddôl sun-disc was found here, a gold ornament more than 4,000 years old and the earliest gold object yet recorded in Wales. Fourteen hectares are a Site of Special Scientific Interest, and the mines now belong to the Cambrian Mines Trust, formed in 2012 and buying the site from the Crown Estate the following year.
Look at it from the road, and no closer
The mine is not an attraction and it is not a safe place to wander into. Shafts and adits stand open, the opencast is deep, the spoil heaps are loose and steeply tipped, the masonry is unstable, and none of it is fenced or supervised the way a visitor site would be. It is also a scheduled monument, so damaging any part of it — moving stones, digging in the spoil for minerals — is a criminal offence.
There is a second reason to keep children and dogs on the tarmac: the waste is genuinely toxic. Natural Resources Wales calculates that drainage from the site adds around twelve tonnes of zinc, two tonnes of lead and thirty kilograms of cadmium to the River Ystwyth every year, enough to hold the river below water-quality standards as far as Cardigan Bay. NRW is working towards a mine water treatment system. Until then the advice is plain: stop where there is room, look, photograph it from the road, and go no further.
The Arch, the Hafod estate and where to stop
Proper stopping places on the western half are easier to find than you might expect. Y Bwa, the Arch, spans the B4574 between Devil’s Bridge and Cwmystwyth: a masonry arch put up by Thomas Johnes of Hafod in 1810 for the golden jubilee of George III. Natural Resources Wales keeps a car park and picnic area there, dogs welcome, and three waymarked circular walks leave it — the mile-long Hafod Arch Woodland Trail, the Pwllpeiran Trail through the heritage of the upper Ystwyth, and the mile-long Panorama Trail, rated moderate.
The Arch is also a Dark Sky Discovery Site in the Milky Way class, which makes that car park a far better place to stop after dark than a verge higher up. Devil’s Bridge has car parks, cafés, the Mynach falls and the Vale of Rheidol Railway.
Over the watershed towards the Elan
East of the mines the road changes character completely. Discover Ceredigion describes this section as single track, dropping from a rocky col through a valley carved by ice; driven the other way it is a long climb onto open moorland with no walls and no trees. There are no junctions and no settlements until it comes down to Pont ar Elan and meets the reservoir road at the head of Craig Goch — see our Elan Valley page.
For a gentler inland crossing, try the Dylife mountain road to Llanidloes; the A487 coast road is the easiest route in this section.
What this road asks of a driver
East of Cwmystwyth you are on a single-track road with passing places. Highway Code rule 155 asks you to pull into a passing place on your left, or wait opposite one on your right, to give way to anything coming uphill; rule 156 says do not park in passing places. On a road this quiet it is tempting to treat a wide spot as a viewpoint, and a farm trailer then has nowhere to go.
Sheep graze unfenced ground on the tops and lie on warm tarmac, and lambs bolt towards the ewe rather than away from the car. Cyclists use the route heavily, including loaded tourers on the long climbs; the Highway Code asks for at least 1.5 metres when passing at up to 30 mph. Caravans, motorhomes, box vans and towed trailers are better routed round on the A44. Winter, gates, fuel, signal and breakdowns are covered on our practical page.
Practical Information
The obvious pairing is the red kites at Bwlch Nant yr Arian on the A44, fed beside the lake at 2pm daily; watching is free, parking is charged. More ideas on the driving routes hub and at Llyn Clywedog.
The B4574 runs six miles between Pont-rhyd-y-groes and Devil’s Bridge; the mountain section east of Cwmystwyth is single track. Allow a half-day from Machynlleth out and back, or a full day to add the Elan dams. There is no fuel, shop or public toilet between Devil’s Bridge and Rhayader, so fill up and buy food before you leave town. The workings are a scheduled monument and dangerous: view them from the road only. Legal parking with facilities is at the NRW Arch car park and at Devil’s Bridge. Check a forecast in winter — our weather page explains which one to use.
Day trips