This Gorsedd Circle was erected in 1972 for the Haverfordwest National Eisteddfod. It's located near the town's Old Bridge, on the slip road that leads to the Morrisons Supermarket.
One of the stones used here was apparently a prehistoric standing stone which was taken from Tresinwen in North Pembs. That sort of thing would not be allowed nowadays...........
There are 11 stones in the circle -- all dolerite, I think. One of them is over 2m tall -- that may be the one which was previously a prehistoric (??) standing stone. Several of the other stones are over 1.50 m tall -- big and bulky. There are no dolerites in the Haverfordwest area -- so the stones have probably come from Preseli or Pencaer. Dillwyn Miles (who was involved in everything) probably used his north Pembrokeshore contacts to get hold of them.
There are two external stones adjacent to the main road -- these act as a "gateway" to the circle. There is also one internal standing stone. The node stone is massive -- I reckon it weighs between 8 and 10 tonnes. That must have been a challenge to move -- even with modern machinery in 1972.
The definitive guide to the modern Gorsedd Circles of Wales:
https://sublimewales.wordpress.com/attractions/18th-and-19th-century-stone-circles/gorsedd-circles/
Michael Freeman has done great work on this, and his beautifully illustrated blog is well worth a visit.
See also:
The huge node stone and the steps -- used in the Gorsedd ceremonies. One of the stones looks like a basalt -- it might have come from a local quarry. The other stones have most likely come from the surface litter.
Several of the stones have obvious signs of modern breakage, with fresh jagged edges that are very sharp as compared with the rounded off edges of stones that have been exposed to surface weathering and cosmic bombardment for thousands if not millions of years. Old surfaces and newer surfaces have distinctive weathering crusts and different degrees of recent lichen coverage.