The Ring of Brodgar Orkney

The Ring of Brodgar, is on Mainland, the largest of the Orkney Islands, in northern Scotland. It is thought to be a lunar observatory dating back to 1500 B.C. The stone ring was built in a true circle, almost 104 metres wide. Although it is thought to have originally contained 60 megaliths, this figure is not based on archaeological evidence. Today, only 27 stones remain