2-645-313 - © CM Dixon/Heritage Images

Castlerigg Stone Circle near Keswick, Cumberland, UK, 20th century. Constructed as a part of a megalithic tradition (3,300 to 900 BC,) during the Late Neolithic and Early Bronze Ages, and is one of the earliest stone circles in Britain and possibly Europe. The circle may have been a meeting place where axes were traded or exchanged.