Cwmorthin

Hanging valley of ruined barracks, chapel and quarry buildings around a dark lake, known locally as the slaughterhouse for its accident rate.

Distance: 3.7 mi / 6 km
Time: 2 hr 20
Ascent: 300 m
Difficulty: Demanding
Shape: There and back

Where it is

The circle shows the general area, not the exact start. Use the directions link below to get to the car park itself. Contours and paths shown are OpenTopoMap, drawn from OpenStreetMap data.

The route

A track climbs from Tanygrisiau into the cwm past the lake and the ruins, continuing to the Rhosydd workings above. the way back is the way you came.

Worth knowing

Cwmorthin quarry had a fearsome safety record, which is where the local name came from.
The buildings and shafts are unstable and unfenced. Look, do not enter.
The valley is dark and cold even in summer, which adds to the atmosphere.

What you’ll see

The lake, ruined barracks and chapel, quarry inclines, and the Moelwynion above.

Background

Cwmorthin worked from the 1810s and closed in 1939. Men lodged in the barracks all week and walked home at weekends.