Who built the stone circles and what purpose the did stone circles serve?
The stone circles were built by the people who lived in the stone and early bronze ages. The earliest stone circles appeared about 5000 years ago. Exactly what purpose the circles served is a subject of some debate. The most favoured hypothesis is that they formed religious or ceremonial centres for the local population. There is also evidence that they may also have been involved in trade and interaction between different communities. Other ideas include that they were used to measure the movements of astronomical bodies. There have been suggestions that they may be connected with 'earth energies' (see below). Whatever the purpose the circles served what is beyond doubt is the huge amount of energy and effort needed to construct them. Exactly how precise their construction was is under some debate. When Alexander Thom undertook his famous survey of British circles in the 1960s he was struck by how precise their construction appeared to be. Some of the circles he measured were in fact ellipses or flattened circles. He suggested that their construction might have needed an advanced knowledge of geometry. Also he noted that a standard unit of length (the so called megalithic yard - 0.829 metres) was probably used in circle building. In addition many of the circles were seen to be aligned in such a way as they could be used to measure the movement of celestial bodies. The significance or otherwise of these alignments is a subject that is still the subject of controversy. Whatever the purpose the circles served they were obviously of great importance to their builders. The best advice I can give is go and visit the sites, read about them and then make up your own mind.
What are henges? What relationship do they have to stone circles?
A henge monument consists of an open circular area surrounded by a bank and (usually) an internal ditch. Such a configuration would be impractical for defensive purposes. It is more likely that the henges were used as gathering places by a particular community who used them for the same purposes as stone circles. Henges and stone circles are intimately related and represent two means of constructing the same type of monument. The construction of a henge requires a large flat space and extensive earthworks whereas a stone circle can be built upon land of various topographies. This is reflected in the geographical distribution of the two types of monuments. Henges are found in the lower lying areas of southern and eastern Britain and similar locations in Ireland. Stone circles are more typically found in upland areas towards the north and west.
There is an overlap in the distribution of circles and henges. In this area a circle-henge was frequently constructed in which a stone circle was built along the inner circumference of a henge ditch. Many of the most spectacular surviving monuments are circle henges. The famous monuments of Avebury and Stonehenge in southern England are both circle-henges, while further north Derbyshire's Arbor Low, the Ring of Brodgar and the Stones of Stenness are all circle henges.
Are the stone circles all built in the same way?
The answer here is no. The way in which circles and henges were built varies with both time and geography. In Cumbria, where some of the oldest circles are to be found, the early circles are frequently formed of many relatively tall stones with stones defining a distinct entrance perhaps in an echo of a henge. Later Cumbrian circles tend to have a smaller diameter and be constructed of smaller stones. The stone circles of Aberdeenshire follow a consistent design template with a recumbent stone at the south west of the circle. Elsewhere in Scotland circles of four stones (four posters) are common, whereas the Irish preferred five stones. Stone circles built near to the henge zone tend to be larger than those built away from it. Henges also vary in their construction. A typical henge consists of a circular central space surrounded by a ditch and a bank. However some Irish henges have a bank but no ditch. Early henges tend to have one entrance whereas the later ones have two or even four. At some sites a combination if traditions is present.
Are the ancient stones related to unusual energies that can be detected by dowsing?
In recent years claims have emerged that stone circles may have a most unexpected characteristic. Much has been made of ideas such as ley lines and the idea that they act as conduits for some form of energy. Since many stone circles lie on such lines suggestions have been made that the may act as foci for such energies or be nodes on a network. Needless to say these ideas have received the short shrift from many archaeologists who believe them to be nonsense. On the other hand many devotees of the idea have claimed that they have been able to detect unusual light and sound phenomena at the circles. Many dowsers also claim to be able to use their rods and pendulums to detect the energies responsible for these phenomena.
I have always been sceptical of such claims, and indeed of dowsing itself. However I needed to revise my ideas about dowsing when I was given a demonstration of it in action to find water. I was then able to use the technique to find water myself. Of course, I did not know of the existence of this water beforehand and as such had to eat my words! Having addressed my doubts about dowsing I then decided to put the claims regarding energies and circles to the test by bringing a pair of angle rods to Aikey Brae and Tyrebagger. Interestingly I obtained a reaction. At both sites the rods crossed upon entering the circle but then uncrossed after stepping into the circle from between the stones. There was also a line of reaction running across the circle from the SW side of the circle (the site of the recumbent) across the circle to the NE. I have also obtained the crossing-uncrossing reaction when stepping into the Long Meg ring in Cumbria.
So what does this mean? To be honest I don't know, if indeed it means anything at all! The reactions I obtained seemed to be related to the sites. However their meaning or use is unclear. Were they known to the original builders of the site? If so were they used by them? Do they have any relevance to the original use of the monument? To be quite honest nobody can be really sure. Again the best advice I can give is try it yourself and make up your own mind.........