Its interior measures roughly seven metres east to west and a little over three metres north to south, with walls some seventy centimetres thick, built in random rubble and limestone. At the centre of the east gable, which is thick with ivy, the fragmentary outline of a destroyed window survives. Whether that window once held glass, whether prayers were ever said inside these walls, remains genuinely open. The building may have served an ecclesiastical function; it may have been a small church. Nobody knows for certain.

What is known is that it sits approximately thirty metres north-east of an Augustinian priory on the same island. The Augustinians, a mendicant order whose Irish houses multiplied from the thirteenth century onward, would have required ancillary structures around any priory complex, and a small dependent chapel or oratory would not have been unusual in such a setting. A survey carried out in 1944 recorded the building but stopped short of assigning it a firm date or function, noting only that an ecclesiastical use could not be ruled out. That careful hedging has remained the last word on the matter.