boscawen-un stone circle 50.223456,-5.123456. constructed image.
one of the five stone circles left standing in west penwith cornwall. although many more existed but have been lost over the last two centuries. the merry maidens circle is intervisible with it and can be seen just below the horizon and the stones across the circle can be used to locate it [overlay blue line] the merry maiden was once a double circle like the tregaseal circles further west.the stones can provide backsights for many alignment both landscape and astronomical. either across the circle to their opposite number or through the gap between two opposite stones (made possible by the fact that the penwith circles are generally made up of nineteen stones),