just to confuse things even more.
Some of the small blue stones have mortice & tennons on them but are too far apart to ever have been trilathons at stonehenge.
Maybe they were a mini version of stonehenge at Prescelli?
PeteG
The quarries may have been like builder's yards, sometimes. Or those sites where sheds are sold from. "There's a nice circle for sale at Aziz's Yard in Carlisle".