There a total of 12 Stone Circles in Assassin's Creed Origins, which these are a part of the side quest 'Bayek's Promise'. You will need to complete all 12 of these to receive the trophy. The quest will become available after the main story quest 'May Amun Walk Beside You'. To complete a stone circle you will need to use the stars to match the pattern of the stone circles. Unlike other locations in the game, stone circles do not appear on the map after you have synchronized a viewpoint in its vicinity. Below is a video that depicts all stone circle locations and how to complete them.