Dedicated to St Féichín, it measures roughly 3.4 metres east to west and just over 3 metres north to south, making it one of the tiniest surviving ecclesiastical buildings on Ireland's Atlantic islands. What makes it stranger still is the way the building absorbs its own history into its fabric: the headstones of graves that pre-date the church were pulled up and built into the foundations of its east wall, the dead quite literally underpinning the structure raised above them.

Most of the masonry belongs to the earliest of three distinct building phases, dating from the mid- to late eleventh century, though the church itself post-dates the first monastic activity on the island. The west wall holds a trabeate doorway, a term for a flat-lintelled opening without an arch, and that lintel turns out to be a reused cross-slab, an earlier carved stone given a second life as structural material. The east wall had largely collapsed by the time conservation work began, and its small, deeply splayed round-headed window was reconstructed from the recovered window head and sill stone. Against that same east wall stands a roughly square altar, just over a metre across and about 90 centimetres high, with a decorated cross-slab set into its south side and another broken example found face down at its base during conservation. Near the top of the east wall sits an aumbry, a small recess used to store liturgical vessels, though this one has an unusual concealed cavity below it and steps back beyond the line of the north wall in a way that appears to serve no obvious purpose. Excavations uncovered a paved floor surface, two graves in the north corners of the interior, and in the south-west corner the base of a leacht, a type of open-air stone monument associated with early Irish monastic sites and used for commemorative prayer.