On the northern side of that empty island, in a sheltered position overlooking the Sound, sits a drystone enclosure that nobody on record has yet visited to inspect directly. What is known about it comes from a single set of recorded observations, attributed to M. Gibbons, describing a subrectangular structure roughly 38 metres long and 22 metres wide, its walls still in fair condition after whatever centuries have passed since someone built them.

The enclosure is the kind of feature that turns up repeatedly along the Atlantic seaboard, a defined area bounded by a drystone wall, its original purpose left open to interpretation. It could have served as a stock enclosure, a field boundary, or the outer wall of a more complex settlement. A small annexe adjoins it on the western side, possibly the remains of a hut, and short stretches of field walls extend outward from it, running roughly 35 metres to the northwest and 10 metres to the east. That pattern of walls radiating outward suggests this was not a standalone structure but part of a small working landscape, the kind of low-intensity agricultural organisation that shaped islands like Inishshark over generations of subsistence farming and fishing.