This, the ‘Middle Cairn/Barrow’, appropriately enough stands between Crug Melyn and the unnamed ‘Tumlumus’ shown upon the 1:25k map... although quite why it is named... and its substantial western neighbour is not... I guess only local folklore may be able to explain?
Coflein notes:
“Bronze Age cairn or barrow, 17m” [c56ft] “in diameter, standing up to 2” high, has been ‘opened’. [J.Wiles 20.02.02]”