 There are various ruins on the island and the Ordnance Survey mark the remains of "St. Mary's Chapel" on the western side of the island, having been informed in 1851 that the island was a priest's refuge "in the time of Knox".There is certainly a local tradition of the existence of such a building, although Nicolson (2002) believes this to be mistaken and speculates that Eilean Mhuire may have been a pre-Norse hermitage.