A recumbent stone circle (RSC) is a distinctive type of stone circle containing one stone placed on its side. RSCs occur in just two regional groupings at opposite corners of the British Isles: one is in the Grampian region of northeastern Scotland around the modern city of Aberdeen, and the other in the southwestern corner of Ireland, in Counties Cork and Kerry. In both cases, the recumbent stone is generally found on the southwestern side of the circle. In the Scottish circles it is large and set between two tall uprights, known as flankers, that are normally the tallest stones in the circle. The heights of other stones tend to taper away as one goes round the circle, so that the smallest are found on the opposite, or northeastern, side. In the Irish circles, on the other hand, the tapering works in the other direction; the recumbent stone is small and placed in isolation, and the tallest stones are normally a pair called portals on the opposite northeastern side.
The clear similarity and obvious systematic difference between these two groups, together with the fact that they are separated from each other by sea and several hundred kilometers, have generated a long debate about the degree of relationship between them. It seems highly unlikely that such a similar idea could have developed independently in the two places. But was there necessarily direct communication between these two areas? Or was the idea carried by a single influential person or group of people, traders or emigrants, from one place to the other? Although some archaeologists, such as the British stone circle specialist Aubrey Burl, refer to both groups as RSCs, others, such as the Irish archaeologist Sean O Nuallain, prefer to avoid implying such a close relationship and refer to the Irish group as axial stone circles.
As a group, the Scottish recumbent stone circles present us with some of the clearest evidence from Neolithic or Bronze Age Britain or Ireland that the builders of a particular group of stone monuments carefully configured them in relation to a particular astronomical body or event. In this case the astronomical body concerned is not the sun, but the moon.
The view looking out over the recumbent stone and flankers at the recumbent stone circle of Dyce, Aberdeenshire, Scotland.
The RSCs are confined to a small geographical area, about a hundred kilometers (sixty miles) by sixty kilometers (forty miles), and the archaeological evidence, such as it is, suggests that they were constructed within a period of no more than a few centuries, probably in the later part of the third millennium b.c.e. However, it is their configuration that is of primary interest to archaeoastronomers. Their orientation is remarkably consistent. Over fifty RSCs are sufficiently well preserved for us to be able to determine the orientation, and there is a clear candidate for the principal orientation at each site: the axis of the circle through the recumbent stone. With not a single exception, the recumbent stone is placed within the quarter of the circle centered upon south-southwest, that is, between west-southwest and south-southeast. Some have argued that this orientation may simply reflect a relationship with the local topography or the prevailing wind, but this idea does not stand up to closer scrutiny: the topography of the area is varied and the patterns of wind flow are diffused around irregular hills and winding valleys. In fact, the reverse is true: the consistency in orientation that has been achieved over wide area despite the varied topography makes it clear that the sky was used in determining the orientation. At the very least, the builders must have determined the orientation in relation to the diurnal motion of the celestial bodies that defines the north-south axis.
But there is more to it. As viewed from within the circle, the recumbent stone and flankers frame a part of the horizon, so it is a natural supposition that this direction might be the one of significance (though most analyses have also checked the opposite direction). There is always at least a reasonably distant view beyond the recumbent, and quite often the stretch of horizon framed by the recumbent and flankers contains a conspicuous hill. This strongly suggests that it was important to stand inside the circle looking outwards toward the horizon. When one examines the declination ranges of the horizons, then the goal of such observations seems to be revealed: they seem to relate to the motions of the moon. Put simply, the full moon would pass low over the recumbent stone around midsummer each year.
It is tempting to imagine these monuments being used for ceremonies or rituals that took place by the light of the moon on a midsummer evening, when the moon was seen to reach its correct configuration with respect to the circle. Some archaeological evidence backs this up. Scatters of white stone and particularly quartz, which are perceived in some human communities as reflecting or encapsulating the light of the moon, have been found around the base of the recumbent stone at one excavated site, Berrybrae. At another recently excavated RSC, Tomnaverie, the recumbent stone itself contains more quartz than the other stones; at two others, Auchmallidie and North Strone, the recumbent stone is itself one huge block of quartz.
The other feature that reinforces the idea that the people who built and used these circles were interested in the moon is cup marks. There are few cup-marked stones at RSCs; cup marks occur only on the recumbent stone or flankers, or in one case only on the adjacent circle stone. They are never found in other parts of the circle. Remarkably, the orientations of these cup marks from the center correspond quite closely to specific rising and setting points of the moon, namely the most southerly limits, known as the major and minor standstill limits.
However, the image of people dancing by moonlight in a recumbent stone circle on a midsummer night may be a misleading one. Excavations undertaken by the British archaeologist Richard Bradley in 1999-2001 show that at least four RSCs were put up around an already existing feature, such as a funerary pyre or platform. They also reveal quartz scatters at different positions in the circle. Although there is also some evidence that the eventual addition of a stone circle was anticipated from the outset, it may be that we are seeing structures transformed from other materials, such as wood, into stone. This possibility does not detract from the importance of the lunar alignment, but it does alter how it can be interpreted. On the one hand, it reminds us that people must have identified a sacred place and perhaps used it for a variety of ritualistic purposes in order to make the necessary preliminary observations that enabled them to get the astronomical alignment right when it was set into stone. But it is also possible that the erection of the stones may have closed off rather than initiated a period of use, so that the alignment, once set up, was not used by people at all—or at least not by living people.
The Scottish recumbent stone circles are important to archaeoas-tronomers because they provide evidence of a consistent trend of astronomical orientation, one so strong that it is unthinkable that it could have arisen by chance. On the other hand, we will never know as much as we would like about why such alignments were set up or how (or even if!) they were subsequently used. The recent excavations show how, by looking more closely at stratigraphic, dating, and artifactual evidence, we can begin to gain a firmer idea of how particular monuments developed and what people did there at different times. We need this knowledge in order to put our tentative interpretations of symbolic relationships that we find encapsulated in monuments such as the RSCs into a more reliable context.
By comparing different groups of monuments we can also attempt to explore where cognitive principles, such as the interest in the moon that is so clearly manifested at the RSCs, first originated and where and how they were propagated. For example, evidence of lunar-related orientation can be found at the Clava cairns of Invernessshire to the northwest of the RSC area and also at many of the short stone rows found more widely in western Scotland and western Ireland. On present evidence, it seems that the concern with the moon that we see at the RSCs emerged in Britain and Ireland late in the Neolithic period and continued well on into the Bronze Age (from the late third until the mid or late second millennium b.c.e.). This contrasts with the solar orientation of certain monuments such as cursus monuments (Dorset Cursus, for example), passage tombs such as Maes Howe and New-grange, and stone circles such as the group in Cumbria. Such practices extend back to some of the earliest farmers in Britain and Ireland in the fourth millennium b.c.e.
