It is not a grave in any conventional sense, nor a building. A leacht is a type of early medieval commemorative or penitential monument, essentially a structured heap of stones associated with prayer and ritual circuits, and this particular example sits so close to the church that the two feel like parts of a single devotional landscape compressed into a very small space.

The antiquarian F. J. Bigger described it in 1896 as a stone enclosure heaped with stones, and the structure retains that same character today. Irregular granite boulders define the northern, eastern, and southern edges, while the western side is marked by a single large granite slab measuring 1.55 metres in length, tapering slightly as it runs from north to south, both in height and thickness. The interior is strewn with loose boulders. The island, known in Irish as Cruach na Cara, is dedicated to St Macdara, a sixth-century monastic figure whose feast day in late July was historically the occasion for a significant pilgrimage by boat from the surrounding area. The leacht sits within a broader cluster of penitential stations on the island, with four other leachta recorded in the immediate vicinity of the church.