This I got from Fourwinds site Megalithomania. It really is a lovely place to go with a old Church and a holy well nearby.
While I was at the church a wee doe ran out followed by his friend, which was lovely!
As per Toms site this is a turning stone that could be used for cures by turning the stone in the bullaun clock or sun wise and for curses by turning anti-clockwise.
Its very close to the town of Caher on the road to Tippeary Town.
Its not signed posted but follow the OS map and cross the railway line into what looks like someones farm-yard and follow the road/ stream you can see the cell in the distance and the church is on the right-hand side.