← Dive-sites: Croes Y Ddwyafon Quarry


Croes Y Ddwyafon is a small quarry between Ffestiniog and Capel Celyn. Although when it was working, most of the mining occured underground, it has now been partially backfilled, possibly blocking any flooded tunnels. There are a few shafts surrounding the quarry which may have led to some of the works, however most of these have also been blocked. The place seems to have been deserted for many years.

Road access is tricky as there’s a big dip between the road and the rest of the quarry tracks. This shouldn’t be a problem for any 4×4 or short wheelbase vehicle. The quarry tracks themselves are mostly just broken up slate and there are a couple of steep sections – be wary of punctures. The tracks nearest the pit are blocked but you can get a car close enough to walk down into it.

I havent been able to find much information on this quarry as it’s fairly small, especially compared to some of the large scale workings in Blaenau Ffestiniog. It will need to be dived to search for any remaining tunnels but with all the slate waste that’s been piled in it’s unlikely there will be much to see – but finding out is part of the fun.


Croes Y Ddwyafon Quarry from Above

Croes Y Ddwyafon Quarry from Above
Croes Y Ddwyafon Tricky Entrance

Croes Y Ddwyafon Tricky Entrance

Key Metrics

RegionPersonnel AccessRoad AccessDepth (m) *Permission neededLat Long (DD)Elevation (m)
Gwynedd (C)3/5 Okay1/5 DifficultUnknown52.964056,-3.858022424

Site Maps


Croes Y Ddwyafon map showing tracks


(Click the ‘Lat/Long’ data in the ‘Key Metrics’ section for Google Maps directions)
The quarry can be reached by taking the B4407 turnoff from the B4391, between Ffestiniog and Capel Celyn (The junction with the little cafe). Heading north on the B4407, the quarry grounds are immediately to the right. From the road, the track can be seen as well as the dip in the track which will need to be approached carefully.
The site map shows a rough layout of the tracks and shows any blocked or challenging sections in red, as well as the on foot only portions in orange.
The south most sections of track seem to offer the easiest path to the quarry.

Additional Risks

  • Challenging road access


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