There were commonly three floors. The basement was for stores. The central floor contained the principal apartment, usually with a fireplace, and sometimes with mural chambers, one of which is almost always a garderobe. The flues of the fireplaces and the shafts of the garderobes are often vertical, and contained within the wall. The upper floor was either for the soldiery or for a bedroom for the lord. The walls are ordinarily 10 feet to 12 feet thick, and there is often a well stair—as at Skenfrith, in Monmouthshire—from the first floor, leading to the upper chamber and the battlements. In some of the ruder towers—as in that by the church of Aghadoe, near Killarney, the ascent from the first floor is by the narrow steps projecting from the interior face of the wall into the chamber. In the larger towers, as at Coucy, there is often a small chamber in the wall, over the main entrance, for the working of a portcullis. Now and then the staircase begins at the ground-level, ends at the first floor, and begins again at the opposite side, as in the rectangular keeps. Thus no one could leave his post on the battlements without the knowledge of the captain, who lived in the main chamber. Where the cylindrical tower formed the donjon or keep, it was commonly placed within the area, as at Brunless and Skenfrith. At Coningsborough it stands upon the outer wall; at Pembroke on the wall of the inner ward; but in neither case is there any communication between the tower and the rampart of the wall. At Coucy the tower stands on an inner wall, but is girt about with a low concentric wall covering the foundations. At Launceston the annular space thus created between the tower and the girdling wall was roofed over, and there is something similar round the tower of Penrice in Gower. At Tretower a round tower has been built within an older rectangular keep, and the space between roofed over. In these cases the outer wall was about half the height of the tower. At Lillebonne and Coucy the tower has its proper ditch.