Nine Travellers

The Nine Travellers was the common name given to the stone circle in Boscombe Moor, one of the Three Gorsedds of Prophecy. Despite the common name, the number of stones changed between surveys. Three of them were at one time actually alien lifeforms known as Ogri. Cessair of Diplos was turned into one of the stones by the Megara. They were known to have been included in pagan rituals. (DW: The Stones of Blood)

Behind the scenes
The Rollright Stones site known as the King's Men was used in location shots for The Stones of Blood. The Nine Travellers themselves were added for filming.