While the Office of Public Works has repaired and repointed most of the priory's buildings, a drystone rectangular structure at the northern end of the site has been left largely as found, its rubble walls unrestored, its interior obscured by tombs and graves, its southeastern wall almost entirely lost. It is a small but telling detail: one corner of a medieval priory complex that remains, in a very literal sense, unfinished business.

The wider abbey was founded in 1210, or shortly afterwards, as a priory of the Arroasian Canons of the Order of St Augustine, a reform congregation that followed the Rule of St Augustine and spread across Ireland and Britain from the twelfth century. Its origins, however, reach back considerably further and to a far more dramatic location. Before the mid-eleventh century, the early monastic community of Skellig Michael, the extraordinary island hermitage rising from the Atlantic roughly twelve kilometres offshore, was transferred to this mainland site, the hazardous conditions on the rock having apparently made continuous habitation untenable. The priory nonetheless retained possession of the Great Skellig and kept the Latin alias 'de Rupe Michaelis', meaning 'of the Rock of Michael', a reminder of its oceanic inheritance. The buildings that survive today span the thirteenth to the fifteenth centuries, and the unrestored rectangular structure near the graveyard's northern wall is among the more enigmatic of them. It measures at least 8.4 metres northwest to southeast and 5.2 metres northeast to southwest internally, with roughly coursed rubble walls between 1.4 and 2 metres thick. A gap midway along the southern wall may mark an original entrance, and a short run of walling projecting from the northeast wall hints at an internal division, though what function the building served remains unclear.