There are quite a few shafts and holes all over that can be a danger to animals and people.
There are two shafts in particilar that I think are dangerous and could do with a fence around them. These are the two shafts that go down from approx level 2 to the floor 4 adit dam at Rhosydd slate mine. One of them funnels down from quite a distance. And once you would start to slip there is no way of stopping.
About 20 years ago we let down a video camera down the square top shaft and found there were quite a few dead sheep at the bottom.
These shafts are near to the path taken to walk to the summit of the Moelwyn.
Another dangerous place is on the surface on top of Cwmorthin mine near the border of Oakeley and Cwmorthin where there are many large deep cracks on the surface after the 'big fall' about 1890.
Bellach dim ond swn y gwynt yn chwibian, lle bu gynt yr engan ar cynion yn tincian.