It seems likely that the hermitage was built later than the monastery; given the presumed difficulty of its construction, which would have involved the movement of large pieces of stone up almost sheer cliff faces, the builders would have needed the monastery as a base. The eroding effect of frost on the island's major fault line provided the masons with large amounts of materials for the construction. The interior of the main building measures 2.3 meters long and 1.2 meters wide. The enclosure wall is made from mostly small stones. Although it is now worn and mostly knocked down, it would once have been 1–1.5 meters high. The interior is today full of stone rubble fallen from the structure and the fragments of a 7-foot tall stone cross. The leacht outside of it was probably used as a shrine or altar; it is too small to have been a burial site. The outer terrace is situated on three stepped ledges some distance from the main complex and is difficult to access. Its only masonry consists of a 17-meter-long wall along its steep and exposed perimeter. Wondering why such an inaccessible and harsh outpost might have been built, the historian Walter Horn wrote that "the goal of an ascetic was not comfort" and recalled that the Cambrai Homily states: "This is our denial of ourselves, if we do not indulge our desires and if we abjure our sins. This is our taking-up of our cross upon us, if we receive loss and martyrdom and suffering for Christ's sake." Skellig Michael remained in the possession of the Catholic Canons Regular until the dissolution of Ballinskelligs Abbey in 1578, a result of the reformation by Elizabeth I. Ownership of the islands passed to the Butler family (for rental of "two hawks and a quantity of puffin feathers yearly"), with whom it stayed until the early 1820s, when the Corporation for Preserving and Improving the Port of Dublin (predecessor to the Commissioners of Irish Lights) purchased the island for £500 from John Butler of Waterville in a compulsory purchase order. The corporation constructed two lighthouses on the Atlantic side of the island, and associated living quarters, all of which was completed by 1826. In 1871, Lord Duraven, in his "Notes on Irish Architecture", made the first comprehensive archaeological survey of the island. Describing the monastery, he wrote "the scene is one so solemn and so sad that none should enter here but the pilgrim and the penitent.