Arthur's Stone, Gower

On looking into the Paviland Moraine, I came across a number of references to Arthur's Stone, on the Gower -- a very large erratic of Namurian gritstone (I think) apparently derived from the North Crop of the Coalfield.  According to Prof David Bowen there are many other erratics from this source in the area of the Paviland Moraine, indicating that the ice that carried them came down from the north towards the South Wales coast.  It seems that this was one of the largest capstones in Wales, which at some stage has broken into two or more pieces......

Does anybody know anything more about this feature?  It looks like a rather crude Neolithic burial chamber.  Apparently there are a number of other burial mounds and later features (Bronze Age?) in the area.

Update:  According to the GCR for the Quaternary of Wales,  there are abundant Namurian "quartzite" erratics in and beyond the Paviland Moraine -- the key source is assumed to be Mynydd-y-garreg in Carmarthenshire.  Some boulders of this same rock type are found on the foreshore at Western Slade.