Cae Coch Sulphur Mine

Location
SH 7753 6530 Trefiw, Conwy

Directions
You will need an O/S map as there are several entrances on a hillside of the Gwydwr forest along public footpaths, all of which are remarkably difficult to find. Drive into trefiw and turn up a hill by the “Fairy Falls Inn”, then get your sat nav out and enter the above co-ords.

Access
All ungated, no known permissions required

Suggested Equipment
None

Length
Unknown

Flood risk
The bottom adit (which is still high on the hill) is flooded (in summer) to knee deep. No known flood risk.

Mine Attributes
An old Iron Pyrites mine (fools gold) and sulphur mine. Four apparent levels (base level connects to a level above (adit) which is flooded to knee deep and collapsed) but it also connects to the main workings above that. There is another smaller adit and workings above again but appears to be un-connected.

The water in the bottom adit and chamber is bright red and the water and mud are acidic. There are pools of un-disturbed red water within the mine which are extremely acidic.

There are a vast amount of fantastic formations and this mine is superbly decorated.

Description
The main area of this mine is, essentially, a huge mined cavern. However, many areas were left in situ to retain the structural integrity of the mine and it is possible to become dis-orientated.

The spoil left inside the mine is rich in minerals and whole areas of walls are decorated with amazing formations and colours.

The uppermost adit is knee deep with gooey mud and remains largely unexplored but appears to be unconnected to the main mine.

The “main” area of mining took place below this where you can wander around a huge cavernous area of passages (an apparent contradiction). In the farthest corner (you can follow the run of water) a passageway leads down to another adit level which is blocked at the surface (and therefore flooded to knee deep) although the passageway continues downwards beyond even that to another cavernous area flooded knee deep with bright red water and out to the mountain side.

No equipment is needed but all mud should be removed from clothing to prevent the acidity burning material on exit.

Truly spectacular.

Unexplored Passages
1) The uppermost (probably isolated) adit
2) Undoubtedly areas of the mine missed on the once only visit

Digs
None known

Links
Subterranea Britannica

aditnow

Mine-explorer