Walk straight through the main monastic settlement and cross the wooden bridge over the Glenealo river and there it is. The first of the font-like stones, it's surrounded by a heap of 'megalithics' that may or may not pre-date the christian settlement in their arrangement.
The river flowing from the Upper Lake divides St. Kevin's Kitchen from the Rhefeart church: near the bank of the rivulet, a stone is shown, called the deer-stone. The origin of this denomination is derived from the following circumstance:
-- The wife of a peasant having expired in the pains of child-birth, the surviving infant was left destitute of its natural mode of nurture, nor could any equivalent substitute be procured. The disconsolate father applied to the revered spirit of St Kevin for relief, and was directed to attend at a certain hour every morning, near the Rhefeart church, at a stone having a little circular indenture in the top, into which a deer would regularly shed her milk, and leave it for the infant's use: the little destitute is said to have been nourished by the milk procured at this stone, which is hence called the deer stone.
And there's a little more stoney folklore nearby:
On the way to the Rhefeart church, another of the miracles wrought by the sainted Kevin is exhibited: - A number of large stones, extremely like loaves of bread, and possessing marks analogous to those made by the adhesion of loaves to each other in the oven, are scattered on the ground.
It is related that St. Kevin, having met a female bearing five loaves in a sack, and inquiring the contents of the sack, she answered that they were stones; for it being a time of scarcity, she feared to tell the truth; upon which the saint replied, "If they be not so already, I pray that for your perfidy they may become so;" when instantly five stones rolled out of the sack. These clumsy relics were preserved for many years in the Rhefeart church, but now lie at some distance from it down the valley.
From p127 of 'A guide to the county of Wicklow', by George Newenham Wright (1827) - you can read it at Google Books.