From Junction 42 of the M4 take the B4290 north (via the A483).
The Cairns are to the west of this road; the other side of trees, up a very steep slope.
I headed up the B4290 and thought my luck was in. Just about where I wanted to park was a large lay-by. There was also a convenient hole in the fence and I started to make my way up the steep slope. However, I didn’t get very far!
The brambles at the bottom of the slope were quite short and, even in shorts; I was able to navigate my way through them. As I ventured up the slope the brambles got bigger and were soon chest height – no chance of access this way.
I returned to the car and continued up the B4290.
However, there were no other parking places to be had and the road was surprisingly busy.
Probably the best way to visit would be via Gelli-bwch Farm to the north.
There is no public access to the Cairns and therefore permission should be sought.