I think I’ve spotted this site from the road, but it’s firmly within the boundaries of a field with no public acess. One of these days I’ll knock on the door of the house near the circle and ask if I can get a closer look. Coflein describes it as...
A cairn circle 13m in diameter. Of an original ring of stones protruding from the upper edge of the bank, nine remain.
In his excellent book Prehistoric Preseli (ISBN 1 899793 06 2) N.P. Figgis also describes Glandymawr:
There is another group on the north side of Glandy Cross, running uphill behind the pub. One of these seems to have been of exceptional importance; the platform is kerbed with unusually heavy stones, so that it has sometimes been mistaken for a stone circle. A hedge has cut off some of it, and brambles have swallowed the interior.