The Cathedral, standing within the enclosure, is considered to have been erected about the commencement of the seventh century, and appears, from its name, dimensions, and position, to have been originally the _Domhnach-mór_, or _Daimhliag-mór_, or chief church of the place. Notwithstanding its present state of dilapidation, there are in Ireland few structures of the same antiquity and extent that retain so many original features. The nave is 48 feet 6 inches by 30 feet; the chancel--25 feet by 21½ feet--appears to be of later date; the fallen arch has been restored to about eight courses above the piers. It is entered by a square-headed doorway, 6 feet 9 inches high, in which the weight upon the lintel is taken off by a semicircular arch. The masonry of the chancel is much less massive than that in the body of the church, and, moreover, is not bonded into the nave, thus showing its more modern erection. The east window was remarkable for its ornamental character, possessing a chevron moulding and a sculptured frieze running on either side from the spring of the arch. The most interesting building in the enclosure is St. Kevin’s House or ‘Kitchen.’ This has been to all intents and purposes changed into a church by the subsequent addition of a chancel and bell-turret, neither of which, in all probability, belonged to the original building; the chancel has been destroyed, but it will be seen on close examination that the walls of the adjoining sacristy are not bonded into those of the main building. ‘It will be observed also that the chancel arch is of subsequent formation; for its semicircular head is not formed on the principle of the arch, but by the cutting away of the horizontally laid stones of the original wall, in which operation a portion of the original window placed in this wall was destroyed, and the remaining portion of the aperture built up with solid masonry.’[123] The arch is 9 feet high by 5 feet wide. St. Kevin’s House was thus originally an oblong building, 23 feet by 15 feet, with a very high-pitched stone roof, a barrel-vaulted room below, and a small croft between. It was entered by a door on the west side, which is now blocked up; it was square-headed, with the weight taken off the lintel by a semicircular arch, as in the cathedral door. Above the west gable is the addition of a small round-towered belfry, rising 9 feet from the roof. The sacristy was apparently similar to the chancel, being stone-roofed and ornamented with a rude string-course similar to that of the main building. It is considered by Petrie that these additions took place after the death of St. Kevin, whose name was held in such reverence that naturally it was sought to convert his residence into a church.