This boulder sits by the side of the road, a short distance away from my house. When we first moved here, our neighbour, May Connolly, who has lived here for over sixty years, told us that this is a Wart Stone. The small indentation in the stone fills with water, and it was traditionally believed that if you have a wart, and bathe it in this water, it will go away.
The indentation is a perfect sphere. It's a beautiful stone, and easy to see how it could be interpreted as a healing place.