A reservoir road on the roof of the Cambrians
North-east of Aberystwyth the A44 climbs inland towards Llangurig, reaching its highest point at Eisteddfa Gurig, which Discover Ceredigion gives as 1,339 feet or 408 metres. Just short of that, an unclassified road turns north off the A44 near Ponterwyd and runs about three miles up to Nant-y-Moch reservoir, crosses the dam, and carries on over open moorland to drop down to Talybont on the A487. It is one of the least-travelled tarmac roads in Wales, and one of the most exposed: this is the Pumlumon block of the Cambrian Mountains, where Pumlumon Fawr reaches 752 metres (2,467 feet) and the Cambrian Mountains Society describes plateaux that feel wild, empty and isolated, with large areas reachable only on foot.
From Machynlleth the neat way round is a circuit: south on the A487 and inland on the A44, over the reservoir road, and back to the coast road at Talybont. Allow most of a day, and do the stopping rather than the mileage.
The dam, and the hamlet under the water
Nant-y-Moch dam was built between 1957 and 1961 as the gathering point of the Rheidol hydro-electric scheme. Coflein records it as a concrete dam 52 metres high and 351 metres long, holding up to 26,000 million litres across 275 hectares of water. Statkraft, which has owned the scheme since 2009, puts the same figure on the reservoir and describes ten buttresses seven to eight metres thick, 152,000 cubic metres of concrete and more than 500 men on the dam alone. The wider scheme cost around £10 million, employed over 1,800 people and was formally opened on 3 July 1964; today its three power stations total 49 MW and generate around 93 GWh a year.
What the water covered was a hamlet of the same name. The contents of its burial ground were moved to the chapel at Ponterwyd, and a number of cairns, some of them dating back as far as the Iron Age, were taken apart and rebuilt above the new shoreline. On a grey afternoon with the level down and the old field walls showing, that history is not hard to feel.
Red kites at Bwlch Nant yr Arian
The obvious stop on the A44 leg is Bwlch Nant yr Arian, the Natural Resources Wales site above Ponterwyd, nine miles east of Aberystwyth. Red kites are fed beside the lake at 2pm every day and there is no charge to watch; expect up to around 150 birds, sometimes more in winter. Parking is charged on a stepped tariff, and the important detail is that the café and shop have closed — what remains is a hot-drink and cold-food unit in the car park with portable toilets, so bring a picnic. Eleven waymarked walking, cycling and running trails leave the same car park, including the surfaced, accessible Barcud trail round the lake.
Hyddgen: the battlefield beyond the dam
The moorland north-east of the reservoir is Hyddgen, where Owain Glyndŵr’s forces defeated a much larger English and Flemish army in June 1401 — the victory that turned a local rising into a national one, and the centrepiece of the Urquhart mural in Machynlleth’s Parliament House. Our Owain Glyndŵr page follows the story from Ruthin in 1400 through to the parliament at Machynlleth in 1404.
There is a memorial stone to the battle at the car park by the dam, unveiled in 1977, and that is as close as a car gets. The battlefield itself is a long walk in along the Hyddgen and Hengwm valleys, over tussock, ditch and bog; two white quartz blocks known as the cerrig cyfamod, Glyndŵr’s covenant stones, were set up to mark the site, although the fighting is now thought to have been about a mile further north. It is not a heritage site with facilities. Go in dry weather, with boots, a map and time in hand — our walking page has gentler options.
What the road is like to drive
The A44 section is a normal two-lane trunk road with long gradients and sweeping bends; Discover Ceredigion warns to watch for dozing sheep on it, and perhaps a few Highland cattle. The reservoir road beyond Ponterwyd is a different thing: narrow, largely unfenced, single track in places with passing places, and with cattle grids and gates. Pull into a passing place on your left or wait opposite one on your right, give way to anything coming uphill, and never park in one. There is nothing resembling a service between Ponterwyd and Talybont — no fuel, no shop, no toilet, and phone signal that comes and goes.
Caravans, motorhomes and towed trailers should stay on the A44 and A487 rather than attempt the reservoir crossing; there is very little room to turn round and long stretches with no sensible reversing point. Cyclists and motorcyclists use this road a great deal, and on a blind single-track climb the only safe assumption is that something is coming. Full detail is on our practical page for these roads.
Where to stop, and stargazing
The car park at the dam is the one proper stopping place on the reservoir road, and it is a good one: the memorial stone, a long view down the water, and walking routes heading north. It also sits far enough from any streetlight to be a recognised dark-sky spot, which makes a clear winter evening here memorable in a way daylight does not quite manage. Elsewhere, resist the temptation to leave the car on the verge; the ground is soft, the passing places are needed, and farm traffic works this road all year. Talybont, at the northern end, has a village green and two pubs.
Practical Information
Turn north off the A44 near Ponterwyd for Nant-y-Moch; the dam is about three miles up. The circuit from Machynlleth via Aberystwyth, the A44, the reservoir and Talybont makes a comfortable day with stops at the kite feeding and the dam. There is no fuel or food between Ponterwyd and Talybont, so fill up and buy supplies first. The reservoir is a working hydro-electric asset: keep to the road and the car park, and take the same care near open water that you would anywhere. Winter here is genuinely cold and exposed, and the unclassified road is not a gritting priority — check a forecast and, if it looks marginal, take the coast road instead. More routes on the driving routes hub.
Day trips