Distance: 27km (one-way).
The highest summit in southern Snowdonia, Cadair Idris (also known as Penygadair) is no secret. We wish it was, but it isn’t. Looming large above the twin lakes nestled breathtakingly beneath its crags, with staggering views of the Llŷn Peninsula and with two well-trodden trails snaking up to the top from the trailheads of Ty-nant (north side) and Minffordd (south), this is deservedly a mountain that woos the walkers with hundreds of visitors on peak days in summer. It even has its own visitor centre (Minffordd). But even with popular destinations, Undiscovered Wales find there is normally a means of seeing them in a way which evades the masses. What follows is a rugged route guaranteed to get you up this iconic mountain without clapping eyes on a handful of other hikers tops (we did it on a post-lockdown Saturday in July and passed one other walker and a birdwatcher). This path approaches from the east, at Mallwyd, traversing sections of forestry, spectacular ridge walking and three significant summits of its own before delivering you up, after a drama-charged day of trekking, to Cadair Idris.
Mallwydd is in the extreme south of Snowdonia: much further south, and you wouldn’t be in Snowdonia anymore. As the nearest part of National Park to where we live, we have developed quite an affinity with this gentler, greener, less-visited area at Undiscovered Wales. On our third visit to Cadair Idris, we wanted to come up with a way of getting there that captured the imagination of the more adventurously minded hikers that wanted an alternative to the standard, busy trails up. Mallwydd, 2km south of Dinas Mawddwy, offers a great start-point: the white-washed, timber-framed Brigands Inn, with a large car park right on the main A470 roundabout in the village. A garage 100m up the road on the A458 also offers snacks for the trail. Because of the length of this hike, we recommend staying in Mallwydd the night before. Then either wild camp around Cadair Idris or stay down in Ty-nant on the north side of the mountain for the night of the hike (we recommend the Gwesty Gwernan Hotel having stayed there) – the next day, you can return to the Brigands Inn either by walking or by taxi/public transport via Dolgellau. DO take provisions for this hike and DO take a compass – you will have great need of both!
From the Brigands Inn, cross the main road (see the sadly neglected bench across the way?). Begin along the minor lane bearing southwest through verdant fields. This first section (and the last) is on the Cambrian Way, the trail that runs across Wales from Cardiff in the south to Conwy in the north. About half a kilometre down this lane you come down to the river, cross it on a stone bridge, and turn left (uphill) at the T-junction immediately after. Just up from here a couple of tracks cross the lane. One angles left (don’t take this, it goes to a B&B) but on the right is a gateway with a Cambrian Way marker which angles sharp right up away from the lane. Take this and immediately enter woods, where a series of enclosures are brimming with game birds. Continue northwest on the main track gradually uphill alongside enclosure fences a few hundred metres to a point where the track divides, with the straight-on option bowing to cross a stream ford. The other option is a track swinging steeply up to the left. This is your track.
This track curls right around to quickly ascend onto moorland, where a collapsed stile stands ahead on the other side of a part-broken fence and a quadbike track curves steeply up the hill you are on. Do not take the quadbike track: you are not aiming for the summit of this one! Rather, pass the style and then climb west northwest up the bracken-cloaked hillside, aiming initially for a stone wall and ladder stile by a clump of trees and then, further up and further into the bracken, another couple of larger trees. At this point you are skirting the upper slopes of the hill above you to the north but never coming close to its summit. Pass the first tree, then find a faint path through ferns about 10m above the second tree (it’s better to aim higher if in doubt, you can descend in the clear ground after the ferns). You’re aiming now for the nearby forest line of an outpost of the Dyfi Forest and you’ll reach a stile taking you into the trees on an overgrown but distinct path that twists down to reach a broad forest track at a waymark. A path is shown on maps continuing straight over the other side of the forest track but in reality new-plant deciduous forest has obscured the first part of it and you will search for it in vain. Instead, head up the forest track until just after it kinks to the right after about 150m. Now look for a firm firebreak (a gap left between lines of conifers) and make your own way, slithering somewhat, down this firebreak whereupon, after negotiating a few fallen trees, you will see the path you should have been able to follow from the forest track. Take this to descend to another narrower forest track at the point where it carries out a U-turn before arriving at a house.
This is Ty-Mawr, and the path scampers just to the right of this reasonably furnished but seemingly abandoned property, skirting the oil tank, and joining a peaceful grass-and-stone track on the further side. A stream also trickles along this path as you proceed down it, across a field, to a grassy bridleway and stream. Do not bear right or left through gates here, but continue up along this bridleway to pass first one and then a second ruined croft with the stream increasingly now below to the right. After the second croft, the track goes through a gate and deteriorates somewhat to keep rising between two further ruins, then bend up through clear-cut forest to the northwest to meet the main upper track through this section of the Dyfi Forest. Just to the left, another path with a signpost pointing up at an angle to this upper forest track can easily be seen. This bears northwest and then southwest a few hundred metres on a very narrow and slightly overgrown little path, climbing to another waymarker. Here, elect the path which climbs the most steeply, reaching the forest perimeter after 200m at Bwlch Siglen.
Bwlch Siglen is quite a dramatic spot, with the lower valleys snaking away below, the thunder of waterfalls close and the lingering presence of former quarry workings nearby, whilst conifer forest and moorland sweep up alongside each other above you. You also rejoin the Cambrian Way here. Incredibly, as it will seem after what has been no easy ascent, your route now turns straightaway left having crossed the forest perimeter fence and climbs very steeply up this northern edge of the forest. Ascend until the path starts levelling off. Now you will see, ahead to the west, this block of forest ending and a ridge fence. You can at this point either cross the head of a stream to navigate the steep craggy contours of Maesglase, north of here, to climb to the peak of Maen Du (674m) – or you can follow the fence for 1.5km north northwest to reach a fence junction and stile just southwest of Maen Du.
Here a broken piece of wood once provided a way across the bogs immediately on the other side. Sticking to the right side of this fence, follow it west southwest or west, and gradually down at first, on what becomes a dramatic ridge after a while. Forest soon occupies the left hand side of the fence; to your right the sheer craggy cirque forming the sides of the Afon Cerist far below plummet away. At Craig Portas, little more than a fence junction with dizzying views where the western edge of the cirque begins, trace another fenceline down north northwest to a stile alongside the forest (yes, the Dyfi Forest once more). You keep to the moorland with the forest immediately left as you climb to Cribin Fawr, switch direction more to the left and keep on forging along the top of the moor directly above the forest boundary up to Waun-oer (670m). Before the trig point at Waun-oer, there is a dip and then another very very steep and tough ascent alongside the forest edge – lung-busting after what you have already done. But after Waun-oer your reward is vastly improved views of Cadair Idris ahead, and another brilliant stretch of ridge hiking.
Cling to the forest line, crossing two perpendicular fences, to reach after what seems an age along an upland known as Mynydd Ceiswyn a ladder style with a path leading down off the moor to the northwest. Below you can see a cycle path, and the point at which it squeezes between a drystone wall below a tract of forest (easy to see, a little bit of bog negotiation to reach it!). At the path, continue straight on along the left edge of the wall and then soon curve on what stays a defined path to descend to the A487 main road at an old quarry about 100m above a parking place.
Now, cross the road and onto a path to the right of the quarry, which traces the edge of the main road until it passes the brow of the hill. Here you scale another stile on a path which quickly bears away from the main road. Above to the northwest rears the jagged crag of Gau Graig, and from here it seems mighty high (it is not, in reality, much higher than the two other summits you have visited so far). Cadair Idris is west northwest from here but to reach it, you have to bear northeast on a little valley bottom path that appears to be heading anywhere but up a high Snowdonia mountain. This path bumbles along to a farm building and sheep pen after maybe 800m. It crosses the river here but does not pass through the pen to the good farm track beyond (come on, this would be too simple!). Instead, hug the far bank of the river and climb to a stile, where a waymarker points diagonally right up the next field. Follow the marker and ascend the field, with a gap at the right-hand end of a stone wall the objective. Now the route rapidly gets tougher again as you bear north northwest for a short distance up the steepest grassy slope visible, with the aim being to get onto the ridge that rises to your left (along with the bulky mass of Gau Graig). Keep looking left/west to descry a ladder style above a patch of ferns in a fence above. Through this, and a faint path corkscrews steeply up the ridge, skipping between a flurry of crags (many of which you will need to pause at for a breather!). A tough but rewarding kilometre brings you up to Gau Graig on the left, with a fenceline ahead that you now follow southwest along the flat, marshy ridgetop. Now with Cadair Idris dominating the horizon ahead, Gau Graig goes from seeming inaccessibly high to rather small. Follow the marshy ridgetop along and up to another stile, where a very stony path bends steeply up beyond. The way to the top of Cadair Idris is now on this path, first via the already very lofty peak and cairn of Mynydd Moel. After this a broad ridge ushers you directly and now gently up to Cadair Idris, with the crater-like lake of Llyn y Gadair far far away and down to your right. You might even spy a few people up on the summit, wondering how you managed to come up a totally different way!
And once you have gawked at the sensational views from the top, you descend on the stony and well-traipsed Pony Path back down to Ty-nant and the road to Dolgellau. From the point you meet the road, it’s about a mile along the lane right (northeast) to Gwesty Gwernan Hotel, and two miles beyond that to Dolgellau.
NEXT ON THE JOURNEY: From the summit of Cadair Idris, it’s 44 miles northwest to Plas Bodegros Restaurant-with-rooms.
At a glance
How to get there: To get to the start point of this hike at the Brigands Inn in Mallwyd, take the A470 northeast from Machynlleth, the A458 east from Welshpool or the A494 southwest from Chester (coming from Northern England). Mallwyd village lies at the junction of the A470 and A458 (there is a roundabout here, and the Brigands Inn is the big old whitewashed pub on the roundabout.)
Parking: At the Brigands Inn – plenty of it.
Refreshments: The Brigands Inn at the start, along with the afore-mentioned fuel station shop 100m up the road, are the only refreshments on this route, with the next awaiting you at Ty-nant (if you are staying in our recommended hotel, at least).
Best time to visit: Any day with good visibility at any time of year. Of course the hike is possible in grey drizzly weather but the views are so many times more spectacular if you do this one in clear weather.