Hi Tony,
Thank you for your 2 posts. I have checked with some of my contacts in the Donegal area and the collection of stones resembles a court grave site, but there are no listings of such a grave site in the archaeological records for Arranmore.
This does not mean that the site is not genuine, it just means that it has never been recorded or that there is insufficient evidence to suggest that it was once a burial site. So it could be just a collection of stones.
Hopefully some of our other members are able to provide some more insights.