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Clogwyn  Coch Copper Mine, Snowdonia. 

Date of vsits:  04/04/2015,  15/04/2017,  26-28/05/2018  &  14-16/07/2018.

Situated on the northern side of Snowdon, below the cliffs of Clogwyn Du’r Arddu and close to Llyn Du’r Arddu is the spectacular location for this Copper Mine (NGR SH603556). My first visit there in 2015 left me short of time to fully explore the site as it was on a long circular walk from Llanberis, my second trip there was from the Pen-y-pass car park via the Crib Goch ridge, this also left insufficient time so two backpacking trips have since been made, the second, accompanied by Jim Smart.

The mine was worked from ‘towards the end of the 18th century’ (ref. D. Bick), working at least until 1873. In 1830 five levels are recorded as being active. The site today consists of the remains of five buildings, the lower two in the bottom of the valley are larger and may have been a barracks and a mill with a wheelpit, the latter is at the end of a tramway that runs from the bottom of the nearby, well preserved, inclined plane. To the East of the mill, is the breached dam of the reservoir that would have served the mill, evidence of a leat can also be seen. On the slope opposite the incline is a building divided into three rooms, possibly offices. Numerous assorted pieces of ironwork can be seen among the screes beside the incline including a couple of stamp heads, a broken iron pulley and an axle. Near the top of the incline is another smaller but solidly built building. Close by is a level, run-in after about 8 feet, it appears to have been driven straight into the scree slope. There was possibly another level directly behind what would have been the incline drum house.

Higher up, in the cliffs above the incline can be seen several opencut workings, these were looked at but tackle is required for a thorough exploration. Three separate workings were found. To the East of the main workings is a fairly large opencut with some copper staining on the walls, this working is close to the miners track that runs from the top of the incline and joins what is now the Llanberis path that goes to the summit, near the junction is possibly another barracks building.

References –
David Bick, The Old Copper Mines of Snowdonia, The Pound Press, 1982.

Nigel Burns 2019

Llyn Du’r Arddu, with the inclined plane running down the mountainside to the mill.
Upper building, near top of incline.

Opencut working, copper staining can be seen on the left hand wall.


The Level directly under the scree slope, Run-in after about eight feet.


Looking down the incline towards the Barracks (left) and mill (right).


Looking up the inclined plane.


High level working above incline.


Stamp head.


Axle near top of incline.


Mill and wheel pit.

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