Pair of fallen quartz menhirs ("Big White Stone") at a very high altitude of 526m. Coflein descriptions:
1. Carreg-wen Fawr is a recumbent quartz stone, 1.4m by 1.4m by 0.5m, presiding over 'a vast featureless desert of moorland'. A second, prostrate, stone, 1.37m by 0.55m by 0.25m, also quartz, was recorded but was subsequently lost. The monument marks the boundaries of Llanwrthwl and Llanddewi Abergwesyn parishes.
(source Os495card; SN86SW3)
2. Recumbent partly buried stone. 1.4m long. 1.14m wide. 0.50m thick. 2 small slabs under N end poss. packing stones. Another recumbent stone 1m E. 1.3m long. 0.5m wide. (SS 9) CARREG-WEN FAWR, 526 m above O.D., is a recumbent and partly buried block of quartz crowning the summit of a hill. It is 1.4 m long 1.14 m wide and 0.5 m thick and has probably fallen to the N. Two small quartz slabs, partly buried under the N. end may be packing stones or broken pieces from the main stone. Only 1 m to the E. is another recumbent quartz pillar 1.37 m long by 0.55 m wide and 0.25 m thick, probably also fallen, so there may originally have been two uprights. O.S.Card SN 86 SW 3. RCAHMW, 1995 - Draft Inventory description.