Cwmorthin Waterfall and Quarry Walk: A Haunting Slice of Slate History from Your Doorstep

One of the most atmospheric short walks in Eryri (Snowdonia) starts right from Tanygrisiau - a waterfall, a silent lake, a lonely ruined chapel and an abandoned quarry once nicknamed "The Slaughterhouse." Here's how to walk Cwmorthin.

WALKING AND OUTDOOR ADVENTURES

Natalie

9/29/2026

Some walks stay with you long after your boots have dried. The walk up into Cwmorthin is one of them.

Starting just a short stroll from BrynEscape, this is a route that has everything: a tumbling waterfall, a still mountain lake, the ghostly ruins of a quarrying community, and a lonely chapel standing sentinel over it all. It's beautiful and more than a little haunting — a place where the silence has weight. If you only do one walk during your stay in Tanygrisiau, we'd quietly suggest this is the one.

The walk: waterfall to lake

The route begins near the foot of the great slate tips, either from the small car park on Cwmorthin Road or by climbing the track up from beside the Lakeside Café. Take the Cwmorthin Road start and you're rewarded almost immediately: the first gush of the Cwmorthin Waterfall, spilling white down the rocks. Keep climbing and a second cascade opens onto a plateau with a fine view back over Blaenau Ffestiniog and the valley below — a good excuse to stop and catch your breath.

Follow the stream up and the valley gradually reveals itself, until you reach Llyn Cwmorthin — a dark, still lake cradled by the mountains. Along its shore stand the roofless remains of Cwmorthin Terrace, once a row of little cottages where quarry families lived, and the ruin of Plas Cwmorthin among the trees. It's astonishingly quiet up here now; hard to imagine the noise and bustle of the working quarry that once filled this valley.

The lonely chapel and the road to Rhosydd

Follow the path along the lake and you'll come to the walk's most poignant sight: a small ruined chapel, Capel Rhosydd, standing alone against the mountains. The quarrymen built and funded it themselves — a place of worship and solace amid the daily dangers of their work. Roofless now and open to the sky, it's one of the most photographed and most moving spots in the whole area.

From here, the more energetic can push on and up to the abandoned Rhosydd Quarry — a steeper climb to a high, wind-scoured plateau scattered with the shells of barracks, mills and machinery. Rhosydd worked its slate for around a century, and the ruins that remain are hauntingly striking, framed by the peaks of Cnicht — the "Welsh Matterhorn" — and Moelwyn Mawr. It feels like the edge of the world up there.

"The Slaughterhouse": a hard history beneath the beauty

The quiet beauty hides a hard story. Conditions at Cwmorthin quarry were so poor, and the death rate so high, that it earned the grim nickname Y Lladd-dy — "The Slaughterhouse." Men worked long, dangerous shifts deep inside the mountain for little reward, and many never came home. That the same men found the time and will to build a chapel with their own hands tells you everything about the community that once lived and worked here.

This is the human heart of the UNESCO World Heritage Slate Landscape of Northwest Wales — not just spectacular scenery, but the story of the people who shaped it. Walking Cwmorthin, you feel it in a way no museum can quite convey. For more of this hidden history, our guide to the hidden gems of Snowdonia points you to more of the area's quiet, extraordinary corners.

Practical tips for walking Cwmorthin

Difficulty and time. To the waterfall and lake it's a moderate uphill walk — allow an hour or so at a gentle pace, more if you linger (and you will). Continuing up to Rhosydd is steeper and rougher, making it a good half-day outing. You can happily turn back at the lake for an easier day.
Footwear. Proper walking boots, not trainers — the track is rocky and boggy in places, especially after rain (and the waterfall is at its most thunderous then).
A serious safety note. The old quarry workings are genuinely dangerous. Never enter the mines, adits, shafts or ruined buildings — they are unstable and unfenced, and this is not a place to explore underground. Admire the ruins from the outside, and keep children and dogs close.
Go prepared. If you are heading up to Rhosydd and beyond, take a map — the paths onto the wider mountain are easy to lose in cloud, and phone signal is unreliable. Carry layers and check the forecast.
Dogs and livestock. There may be sheep on the hillsides, so keep dogs under close control.
Parking — or skip it altogether. The small car park at the foot of the walk is limited and fills quickly, especially at weekends and through the summer. One of the quiet perks of staying at BrynEscape: the walk begins within strolling distance of the cottage, so you can leave the car where it is and avoid the parking scramble entirely — just step out and go.

For where this walk sits among the area's finest, see our Top 10 Scenic Walks near Blaenau Ffestiniog — and for capturing the chapel and ruins at their most atmospheric, our best photography spots in Snowdonia will help you make the most of the light.

A walk you'll remember, right from the doorstep

Waterfall, lake, ruined chapel and a mountain quarry steeped in history — and all of it beginning just minutes from the cottage. Cwmorthin is the kind of place that gets under your skin: beautiful, melancholy and utterly unforgettable. Staying at BrynEscape puts it right on your doorstep, ready to explore whenever the mood takes you.

Ready to walk into a bit of Welsh history?

Check availability and book your stay at BrynEscape, Tanygrisiau — your base for the Cwmorthin valley and the mountains beyond.

How to Say the Welsh Names

Cwmorthin — Koom-or-thin — the valley, lake and quarry above Tanygrisiau (cwm means "valley")
Rhosydd — Hross-ith — the abandoned quarry high above Cwmorthin (dd is "th" as in the)
Chwarel — Chwa-rel — Welsh for "quarry"
Llyn — Thlin — Welsh for "lake," as in Llyn Cwmorthin
Capel — Kap-el — Welsh for "chapel"
Cnicht — K-nicht — the pointed peak known as the "Welsh Matterhorn"
Tanygrisiau — Tan-uh-griss-ee-eye — "beneath the steps," the village that's home to BrynEscape