 The earliest evidence of the presence of man in these upper areas of Glamorgan was discovered in 1963 at Craig y Llyn . A small chipped stone tool found at the site , recorded as possibly being of ' <unk> ' type or at least from the early Mesolithic period , places human activity on the plateau above the valleys . Many other Mesolithic items have been discovered in the Rhondda , predominantly in the upper areas around Blaenrhondda , <unk> and Maerdy , mainly stone age items relating to hunting , fishing and foraging which suggests seasonal nomadic activity . Though no definite Mesolithic settlements have been located in the area , the concentration of finds at the Craig y Llyn escarpment suggests the presence of a temporary campsite in the vicinity . 
