Was the stone known as Cloch a bhile at Lough Gur a symbolic echo of the world tree (as put forward by Michael Dames) or in reality was it an inauguration site of the medieval period?
It could of course be both.
However in The Archaeology of Lough Gur pg 334, Rose M. Cleary argues that the Cloch a bhile may have been used as an inauguration site of Munster Kings and later the Fitzgeralds who along with legendary Gearoid Iarla became "more Irish than the Irish themselves".
In 1573 Gerald fitz James Fitzgerald was released from jail following the 1st Desmond Rebellion in Ireland. He made a daring escape while under curfew in Dublin with the help of Rory Oge O'More and Piers Grace and returned to Munster.
"On his return to Munster, Gerald received widespread support. 'His wife met him at Bealadrohid and they continued to Lough Gur' (McCormack 2005, 132). Edwards (2016, 342) records that when the earl arrived at Lough Gur 'he was greeted by an assembly of local landowners who gathered at the ancient inauguration site that stood close by', and that 'with great ceremony he removed his clothes he had worn since leaving Dublin, his "English apparel", and "put on his Irish raiment". The inauguration site may have been located at Grange, where Lynch (1895, 299) noted that 'an ancient line of Munster kings were inaugurated' under the tree near the standing stone at Cloghavilla."
So there is record of this stone as being linked to the inauguration of local Earls or Chieftains and this is likely to have gone back to the previous Gaelic Chiefs of the area.
The counter-argument seems to rest with Michael Dames book 'Mythical Ireland' where on pg 79 he says
"Cloch a bhile, 'The Stone of the Tree'. It stands two metres high, grey,runnelled and lichened, a reminder of the phantom tree formerly revealed beneath the lough at seven-year intervals. The stone is a permanent reminder of the ideal World Tree, for lack of which all the forests of the world fall into danger. In myth, the divine tree has the power to en-green the entire forest."
Now it does seem that there is folklore related to a tree under Lough Gur and Howard Golbaum on his wonderful website recorded the story in an interview with local man Tom McNamara in 1999.
Under the heading The Stone of the Tree
The Stone "is connected in myth to the magical tree growing on the bottom of Lough Gur, said to rise up to the surface once each seven years. Its moss and liche covered mantle gives it an organic appearance that resonates with the story of "The Green Cloak", as told by Tom McNamara."
However I think there is a "jump" in linking this legendary tree under the lake to Cloch a bhile or Cloghavilla which may not necessarily be justified. I personally had always taken the account by Michael Dames of the myth surrounding the Cloch a bhile at face value (and passed on to many people) but I wonder now whether this was his own interpretation rather than something that was actually recorded in folklore in the area.