Known as the Saints' graveyard, it sits on an east-facing slope immediately east of St. Caimin's church, its perimeter wall rising and falling with the terrain: highest on the western side, where the interior height reaches 1.3 metres, and much lower on the east, where the wall doubles as a retaining structure against a steep drop that may once have served as an orchard. Capped with rough slabs along the northern side, the enclosure has the quiet, purposeful look of something built to last, and largely has.

According to Liam de Paor's 2013 study of the island, the graveyard was laid out and walled in the twelfth century or just before it. The western entrance, a round-headed archway roughly a metre wide and nearly two metres tall, is old, though R. A. S. Macalister noted in 1916 to 1917 that the arch had been repaired at some point and that one of its voussoirs, the wedge-shaped stones that form the curve of an arch, had been taken from the doorway of the nearby enclosure at St. Brigid's church. It is the kind of quiet recycling that was entirely practical in medieval Irish ecclesiastical sites, where good stone was never wasted. The Board of Works later repaired and coped the walls. Within the northwest quadrant of the enclosure stands Teampull na bhfear ngonta, a small church whose name translates roughly as the church of the wounded men, adding another layer of unresolved history to an already layered site.

What makes the graveyard particularly striking to visit is the number of early medieval graveslabs and cross-slabs still lying in their original positions. During excavations on the island in the 1970s, vegetation around these slabs was cleared and the stones were carefully drawn by researchers but left undisturbed. A small number of more recent burials are also present, giving the enclosure a continuity of use that stretches across centuries. The entire island is a national monument in state care, accessible by boat from Mountshannon on the western shore of Lough Derg.