It is as well to be clear about that as the proposition is at best a complex one; the subject has, however, been beset for long enough by what can loosely be called “Controversy”.
There is the body of people who claim too much; Alfred Watkins’ Ley lines will serve as an example. The evidence is not there, but a romantic fringe has grown around the idea to the point where archaeologists cringe at the suggestion that three stones are in line!
There is a body of people that need to be taken very much more seriously; Sir Norman Lockyer surveyed many stone circles and alignments in the early years of the century and attributed to them solar or stellar indications. Some of his observations are useful but are not on their own evidence enough; the questions have to be answered, did these people really do this and if so why?