Map & Elevation
About this Route
The Snowdonia Slate Trail begins at Porth Penrhyn on the Menai Strait, where sailing ships once queued to load roofing slate hewn from the mountains inland. The route strikes south into the Ogwen valley, passing beneath the terraced scars of the Penrhyn Quarry to reach Bethesda after 10.2 km. From there it embarks on a sweeping 126.3 km loop through the slate villages and high moorland of Eryri, visiting Llanberis beneath the cliffs of the Elidir quarries, circling through Nantlle, Beddgelert and the terraced amphitheatres above Tanygrisiau, then turning east through Penmachno and Betws-y-Coed before returning via Capel Curig and the Ogwen valley to close the loop at Bethesda. The full 136.5 km therefore consists of an initial linear section followed by a loop—you finish where the loop began, not where you started walking.
The trail threads together the quarry tracks, inclined tramways and packhorse routes that once moved slate from rockface to port, stitching them with woodland paths, quiet lanes and stretches of open moorland. You will cross high pasture grazed short by Welsh mountain sheep, descend through oak and birch woods stippled with lichen, and walk the stone-ballasted beds of narrow-gauge railways now given over to foxgloves and ferns. Waymarks assist at junctions, but the route demands current mapping and confident navigation, particularly where it crosses featureless moor or picks its way through the industrial archaeology of abandoned workings. The terrain is rugged rather than technically difficult—more a matter of endurance over varied ground than scrambling or exposure—though weather in these hills turns quickly and the higher sections offer scant shelter.
Scheduling depends entirely on how you divide the distance, where you find accommodation, and how conditions affect your pace. Some will split the loop into comfortable inn-to-inn stages; others will carry camping kit and seek landowner permission for overnight pitches. The organiser commonly describes the route as 83 miles, and with 3,289 metres of ascent spread across that distance the Naismith estimate stands at just under 33 hours of continuous movement—a figure that takes no account of rest, weather, or the likelihood that you will pause to admire the view down Nant Ffrancon or the rusty winding gear slowly disappearing into the bilberry. Plan according to your own capabilities and the realities of accommodation availability, and expect the mountains to have their say.
I look forward to the day when walkers and other visitors will bring new life and opportunity to this amazing slate area of ours
Aled Owen, Snowdonia Slate Trail curator
Route Waypoints
Porth Penrhyn sits at the mouth of the Cegin, where a long stone quay once handled the output of the Penrhyn Quarry. The slate left by ship; you leave on foot, heading inland towards the source.
Bethesda grew to house the quarrymen who worked the Penrhyn, and the town marks both the end of the linear opening section and the start and finish of the long loop that follows. Stock up here before committing to the circuit.
Llanberis straddles Afon Rhythallt beneath the stark grey galleries of Dinorwig, its terraces clinging to the lower slopes. The village offers services, and the lake stretches away towards Snowdon's northern buttresses.
Nantlle overlooks Llyn Nantlle Uchaf, with the Vale of Nantlle opening to the west. The route has covered more than a third of its total distance by the time you reach this quiet scatter of houses and chapels.
Beddgelert lies at the confluence of the Glaslyn and Colwyn, a popular village hemmed by wooded hills. At 54.3 km it sits just before the route's halfway point, making it a natural pause if your schedule allows.
Tanygrisiau perches above the reservoir, overlooked by the tiered slate waste of Blaenau Ffestiniog. The pumped-storage scheme hums in the mountain's heart; the village keeps its counsel on the surface.
Penmachno is reached after a substantial 30.1 km stretch from Tanygrisiau that combines two published stages and passes through Llan Ffestiniog. The Machno valley offers a gentler interlude among trees and small fields.
Betws-y-Coed sits where the Conwy, Llugwy and Lledr meet, a Victorian favourite now cheerfully committed to serving walkers. The loop is nearly complete; the return to Bethesda lies another 28.5 km ahead.
Capel Curig occupies open country beneath the Glyderau, the lakes and pastures spread wide under big skies. From here the route runs virtually level to Llyn Ogwen before descending Nant Ffrancon on minor road and the Lôn Las Ogwen cycleway back to Bethesda—a valley return, not a mountain crossing.
Bethesda returns after 136.5 km, closing the loop that began here 126.3 km ago. The slate cottages look much as they did when you left, though your boots will certainly look worse.
Essential Tips
Waymarks assist at junctions, but current mapping—either 1:25,000 Explorer sheets or a reliable GPS device loaded with up-to-date routes—and competent navigation skills are necessary. Moorland sections and old quarry workings can be confusing in poor visibility, and relying on waymarks alone is unwise.
How many days you take depends on where you can secure accommodation, how you divide the stages, and what the weather permits. Do not assume bed spaces or campsites will be available without advance research. There is no general right to wild camp in Wales; landowner permission is required.
The route uses quarry tracks, old tramways, woodland paths, moorland and valley lanes rather than continuous high ridges. Expect stony surfaces, stream crossings, boggy stretches after rain, and the occasional awkward stile. The ascent is significant but spread across the full distance; stamina matters more than technical skill.
Snowdonia's weather is famously capricious. Even sections that avoid the highest summits cross open moorland with little shelter, and cloud can descend quickly. Carry windproof and waterproof layers, and be prepared to adjust plans if conditions deteriorate.
Frequently Asked Questions
Does the route return to the start at Porth Penrhyn?
No. The route begins with a 10.2 km linear section from Porth Penrhyn to Bethesda, then follows a 126.3 km loop from Bethesda back to Bethesda. The full 136.5 km is therefore a linear opening followed by a loop, finishing 10.2 km inland from where it began.
How many days does the Snowdonia Slate Trail take?
There is no standard duration. Scheduling depends on how you divide the 136.5 km, where you find accommodation, your fitness, and the conditions. Some may complete it in three long days; others will take a week of shorter stages. Plan according to your own abilities and the realities of bed availability.
Can I wild camp along the route?
There is no general right to wild camp in Wales. You must obtain permission from the landowner before pitching a tent. Assume refusal unless you have secured explicit consent, and respect any conditions attached to that permission.