The Stone Circle was a ritual structure on the Forest Moon of Endor in the thorn forest used by the Wizards of the Night Spirit. The structure consisted of a circle of stone columns with a massive stone at the head which had a circle cut out of the top of it. There was also a stone table which sat in the center of the circle. The location was used in tandem with the Sunstar to open a rift in space to "otherworld", the devastated planet which the wizards had been banished to long ago. The Sunstar was placed on the stone table and spun counter-clockwise to create this rift.
The stranger once used the Stone Circle to do exactly that, summoning his people and creating a showdown between the wizards and the Ewoks of Bright Tree Village. However, the wizards were defeated, and the wizards were forced back to their otherworld carrying a critical portion of the Stone Circle in the stone table with them.