The name alone raises questions. It sits roughly fourteen metres to the north-west of the island's early medieval church, defined by a line of boulders running along three sides, west, north, and east, while the southern boundary has disappeared entirely from the surface. Inside, a possible cross-wall divides the space, and the eastern half is scattered with rubble. Whether the structure was ever a building in the conventional sense remains uncertain; it may have been a house site of some kind, or the name on the maps may have been applied loosely, intended not for this boulder-edged enclosure at all but for a nearby leacht, a type of low commemorative or devotional cairn associated with penitential circuits at pilgrimage sites.

St Macdara's Island, known in Irish as Cruach na Cara, is a place of long Christian observance, centred on the ecclesiastical remains clustered at the island's south-eastern end. The church there is one of the more architecturally distinctive early Christian structures in the west of Ireland, and the broader site carries the accumulated evidence of generations of devotion, including the kind of outdoor ritual features, leachta, stations, and informal enclosures, that characterise Irish pilgrimage landscapes. A leacht is typically a small, roughly built cairn or altar-like structure where prayers were said during a pattern, the traditional rounds of prayer performed at sacred sites on a saint's feast day. The ambiguity in the cartographic record, whether the "Penitential Station" label refers to the boulder enclosure or to a separate leacht catalogued nearby, is itself telling: these features blur into one another on the ground, their functions overlapping across centuries of use.