Coflein (J.J.Hall, Trysor, 26 March 2) has this to say concerning the much smaller mound (Blaen Bedw) at SO1402954405, just north of the great Giant’s Grave round barrow:
“A earthen mound, measuring 6m square x 1m high, sub-rectilinear in plan.... Its date and purpose are unknown, but it has been suggested that it may represent a prehistoric funerary monument or even a gibbet mound.”
Incidentally – having watched both a tractor and (old-style) Land Rover Defender struggle up the byway – I would highly recommend leaving one’s car at the entrance track to Ty’n-y-coed (just possible upon the verge) unless you are a complete loon.
As for the Giant’s Grave itself... suffice to say I should have come here much sooner. But hey, there are so many upland sites to be savoured around these parts....