I've been reading folklore for many standing stones which I can't track down on the maps. Sometimes they are marked, but only on one sort of map. So sometimes when there's no map trace at all, I wonder whether they might actually still exist in reality anyway. This is one of those times. The location seems quite definite, and it may well have gone unnoticed by a cartographer in its wood.
In a hill called Blackhill which is about a mile in a North Westerly direction from Abbeyleix there lies a famous old stone which a druid and his people used to worship at before the time of Saint Patrick. The stone itself is in a wood which covers all the hill and is now standing upright in the midst of a bunch of thorns on the top of the hill. It is now only about four feet above the ground and is very hard to find.