The Stone Age Observatory. It is well known that a lot of ancient constructions are oriented according to the cardinal points but not long ago scientists turned upon archeological monuments. ... The ancient monuments studied by archeoastronomy had been used for observing the sun and the moon. ... They are called megalits (from Greek "megas" - "great"; "litos" - "stone"). ... The Great Stonehang. ... Orby called it a Heel Stone because he had seen a small hole in it looked like a heel trace. ...