Image of Ballybrack (Dolmen / Quoit / Cromlech) by Rhiannon

Called ‘Shanganagh’ in the article, I think this must be the right cromlech as it matches the shape in Cian McLiam’s photo almost perfectly.

From v2 of the Kilkenny Archaeological Society’s journal.
archive.org/stream/jstor-25489810/25489810#page/n2/mode/1up

Image credit: Henry O’Neill, 1851