The most notable ancient structures of the Historic Period are the Castles of Peel and Rushen. With respect to the former, which stands on St. Patrick's Isle, about 7˝ acres in extent, we have already referred to the mound near the centre of the islet as having possibly been a stronghold since neolithic times. The first buildings of stone would probably be the originals of the Chapels of St. Patrick and St. German, and, next to these, perhaps, the Round Tower on the highest part of the Island. The upper part of the latter has apparently been rebuilt in mediaeval days, but it is likely that it was never much higher than now, resembling in this respect the Towers at Turlough and Dromiskin, in Louth. The tower is built of sandstone regularly laid in courses, the wide jointings filled in with extremely hard shell mortar. Near the top are four square-headed apertures facing the cardinal points, and one other lower down on the N.W. or seaward side. It is, as now seen, more cylindrical than the Irish towers, but its design and use as belfry, and as keep in wbieh relics and valuables were deposited, and into which the ecclesiastics could retire for security, were no doubt suggested by these.
The Cathedral is cruciform, having a central tower, but without aisles or porches. Its internal length is 114ft. 6in., the width at the intersection of the transepts is 68ft. Sin. The height of the tower, including the square belfry turret, is 83ft., and of the choir wall 18ft.; the thickness of the wall 8ft. The Rev. J. Quine thinks the Early English, Decorated, and Norman chancel was built during the Episcopate of Michael, about 1195, and that even then it may have been on an older foundation; but the tower, transepts, and nave were the work of Symon (about 1226), previously Abbot of Iona, which may partly account for the resemblance to Iona, and the position of the Bishop's Palace adjoining the Cathedral on the north. At a later date the so-called crypt was inserted under the chancel, the floor of which was raised nearly three feet. The north transept arch is Early Decorated, the southern and western arches are later work. The fine embattled walls (four feet thick) surrounding the islet are said to have been erected by Henry, fourth Earl of Derby, in 1593. The approach has been ruined in appearance by modern quays and cement work, but one may still see some of the rude steps, cut in the solid rock, leading to the portcullis door of the old square tower, which is supposed to be early fourteenth century work.
Gødred II. died here in 1187, and King Olaf also died at Peel, in 1237. We read of Reginald's descent upon it in 1228, when he burnt Olave's ships and those of all the chiefs of Man. It seems, therefore, that Olave must have had a stronghold here, though now no trace remains, unless the entrance tower is of that date.
Rushen Abbey, on the Silverburn, in the village of Ballasalla and Parish of Malew, dates from the twelfth century, Ivo, Abbot of Furness, having in 1134 received a grant of lands for the purpose from King Olaf. Cumming thinks there may have been some sort of a religious house earlier, though there is no notice of buildings in the Chronicon Manniae (kept by the Monks at the Abbey) till 1192, when it is recorded that the monks were transferred to Douglas for four years, during which they were engaged in enlarging the accommodation at Rushen. The Church was not completed and consecrated till 1257. According to Chaloner's drawings, made in the seventeenth century, there were five towers of rude masonry, with square-headed openings. The only decided architectural detail is a plainly chamfered arch in the Church tower, one apparently of an arcade running North from the tower, three others now in the Grammar School, which was the old Church of St. Mary;
In this vault have been gathered a. few carved stones and other relics recently recovered; also a fine coffin-lid, of which the exact original site is unknown. It is of thirteenth century work, and of interest as being the oldest stone monument of English or Gothic architecture in the Island, and, as marking the end of the old type- illustrated by the Celtic and Scandinavian carvings referred to above. It may have been the tomb of Olaf the Black, who was buried here in 1237, or of his son Reginald, 1248, or, even more probably, of the last Norwegian King of Man, Magnus, buried in the Abbey in 1265.
Bemaken Friary in Kirk Arbory (Cairbre), though founded by the Grey Friars in 1373, has scarcely any remains, and none older than the fifteenth century. In the chapel, now a barn, may be seen the arches of the east windows, north door and window, and a south window-the square-headed trefoil. A wall forming the north gable of the farm house, 4ft. thick, may have belonged to the Refectory. A few of the Parish Churches, such as Malew, Marown, Lonan, and Maughold show portions of walls, lights, &c., of the twelfth, thirteenth, fourteenth, and fifteenth centuries. The ruins of two keeils of later date than those already mentioned are well worth preserving. The first, on St. Michael's isle, near Langness, was in ruins in Chaloner's days (1652-60). St. Trinian's, Marown, is at the foot of Greeba, in a meadow by the high road from Peel to Douglas. It measures outside 75 feet by 24; the walls, about Oft. thick, are built of the local clay-slate, with dressings and quoins of red sandstone, and it is of Early Middle-Pointed style.