The Martyrology of Tallaght, an early Irish list of saints compiled around AD 800, names two figures called Lochan. One of them may have been the founder of this monastery, though the connection cannot be proved. The matter is complicated by a quiet pun: in Irish, lochan can mean a small lake, but it can also refer to a kind of seaweed, exactly the sort of seaweed that would have draped the rocks of this very island at every low tide. The name Illaunloughan thus carries a doubled sense, half saintly and half coastal, that the early monks would have heard immediately.

Look southwest from Illaunloughan and the silhouette is unmistakable, even at nine nautical miles. The twin peaks of Skellig Michael rise in stark profile from the Atlantic, the most famously austere monastic site in Ireland. Illaunloughan was likely a way-station for pilgrims travelling out to that wilder rock, a sheltered stop where the journey could be paused, prayers said, and provisions taken on. Archaeology backs this up. The site's middens contain not only fish and seabird bones, the expected food of a coastal community, but also oats and meat, suggesting more visitors than just the resident monks. Excavation also uncovered evidence of fine metalwork being cast on the island, a craft well above the level of bare subsistence.

The most striking thing the excavators found was a gable shrine built to hold the relics of the community's saints. The structure was decorated with quartz and scallop shells, two materials that travel together far beyond Kerry. The scallop, in particular, was the badge of pilgrims walking the Camino de Santiago across northern Spain, where it signified the road to the tomb of Saint James. Whether the monks of Illaunloughan made the connection consciously, or whether the shell simply carried an older meaning across the Christian west, the result is the same: a tiny Irish island sharing a visual language with a pilgrimage route hundreds of miles away.

The monastery had largely ceased to exist by the 9th century, but Illaunloughan was not abandoned. Up to the 20th century, the island was used as a cillin, a burial place for unbaptised infants, and as a general graveyard for local people. In Catholic Ireland, infants who died before baptism could not be buried in consecrated ground, so families took them by boat to places like this, set apart by water from the parish cemeteries. The pain in that history is real and recent; some of the families remembering a small grave on Illaunloughan are still alive. The dry-stone altars and the gable shrine still stand, weathered to the colour of the rock around them, and the island is now a quiet National Monument.