North

The largest is c.51 metres in diametre, the average is 19 metres.
There can be up to 30 stones in a circle. See also iii)

TABLE of monuments surveyed

Due to their relatively small numbers and sizes, Wales' monuments in this category were, on the whole, studied as part of investigations covering the whole of Great Britain (e.g. A.Burl, The Stone Circles of the British Isles, 1976, pp.254-272). Nevertheless, there are a few studies dealing specifically with Wales, e.g. W.F.Grimes (1963) 'Stone Circles and Related Monuments in Wales' in Ll.Foster & L.Alcock (eds.) Culture and Environment, or F.Lynch (1972) 'Ring Cairns and Related Monuments in Wales' in Scottish Archaeological Forum IV; see also Roese 1980. Yet, circles largely remain enigmas. There is still uncertainty as to whether they are sepulchral or ritual or both. However, a characteristic that one can be certain of is the fact that henge-type circles, including embanked circles, occur in coastal and lowland areas as well as in the immediate hinterland. Stone circles, on the other hand, occur across the whole of mountainous inland Wales, and especially in the heart of the country. Another characteristic, which hitherto has been given scant attention, is the field observation that where stone circles have outliers (a single stone or a row of stones) they are persistently located uphill of the circles themselves. The level at which an outlier has been placed is thus slightly higher than that of the circle. This may be fortuitous but, until it has been proved to be so, it could be significant. Furthermore, the long axis of the individual outlier stones, when upright, appear to be persistently orientated towards the circles. In the case of Cerrig Duon, an associated avenue leads downhill, away from the circle towards a stream and to where the path through the valley always seems to have been located. Following an imaginary central line through the avenue, down the slope & across the stream, on the opposite slope, approximately 1,000 meters from the circle, at 15 degrees to the north-east (SN 82452145), stands another large single menhir on a low hummock. Its long axis is perfectly aligned with the avenue. Today, both monuments are only just out of sight from one another, because the end of what looks like a down-slope moving tongue of peat has crept into the sight line. It is possible that 3,500 years ago this hindrance was not there and that the standing stone was visible from Cerrig Duon and vice versa. Whether or not there is a relationship between the stone circle assemblage and this individual standing stone is, of course, completely unknown. But these are the physical facts in the field.