Theres not much to add to TMA’s entry – only to say that if you’re in Scotland you MUST visit this site. It’s such a cool little circle. It’s partly in a field, partly on a verge,has a B-road running through it, and has been ‘enhanced’ with concrete and steel- and yet it just rises above the last 2 millenia and KNOWS it. awesome.
(Just take a reflective jacket and be prepared to dive for cover)