A leacht is a type of commemorative cairn or structured stone heap, typically associated with early Christian pilgrimage practice in Ireland, where prayers would be offered and sometimes stations walked around the mound. Finding one on Caher Island is not entirely surprising, as the island is known to have been a site of religious activity in the early medieval period, but the presence of such a monument on an island that requires a boat crossing and demands some effort to reach only deepens the sense of a place that once mattered greatly to people whose names are now mostly lost.

Caher Island sits in Clew Bay, that broad Atlantic inlet scattered with drumlins, the low rounded hills left by retreating glaciers that here continue out beneath the water as small islands. The island is associated with early Christian monastic settlement and is considered part of a wider network of pilgrimage sites in the west of Ireland, a network that also includes Croagh Patrick on the nearby mainland. Pilgrimage routes in early medieval Ireland often connected such island and mountain sites, and structures like leachta served as focal points for devotion, marking the memory of a holy person or a moment of significance in the life of a community. What precisely this particular leacht commemorates, and when it was constructed, remains unclear from surviving records.