This carn is about the same size as B, 21 feet high and 68 feet to 70 feet in diameter at the base. There may be a kerb, but if so it is completely concealed by the turf which has grown up round the margin of the heap of stones, to such an extent that the floor of the chamber is some 2 feet below the present average level of the base of the mound.
The entrance faces north-west by north (compass bearings 328°). It is a small hole, confined between a lintel and a threshold very close together; but it gives access to a chamber of considerable size, which is by far the best piece of construction in the whole series. A plan and sections of the carn are given in Plate XXII, and of the chamber on Plate XX.
Well-selected standing stones of a maximum height of 6 feet support a system of lintels and cross-beams of stone, which, rising by oversailing courses, form a chamber very similar to Brugh na Boinne both in plan and construction. The roofing-slabs, as in Carn F, slope downwards to the outside. The main chamber is more or less circular, and three small cells, of lesser heights and separated by high sills from the main chamber, give a cruciform shape to the plan of the structure.
These cells are the receptacles for the interments. Each is floored with a large flagstone, and a similar flagstone occupies the floor of the central chamber. These flagstones were raised, but nothing was found underneath them. Plate XIV, fig. 2, illustrates the construction of the inside of the chamber; but it is impossible to secure a photograph that does justice to the building, which, though it may seem an exaggeration to say so, is beyond all praise as a veritable work of art.
The builders aimed not merely at a building which should remain standing: they evidently took a pride in erecting a neat and symmetrical chamber. In one or two cases we suspected that a single block had been split in two, in order to secure as nearly as possible identical stones for corresponding positions on opposite sides of the chamber.
The fourth standing stone on the right hand side of the entrance did not reach the roof, and inserting the hand behind it we found that there was here a sort of shelf or pocket in the wall, which contained the bones of children. Its outline is indicated by dotted lines in the plan. The space was just under the roofing-slab, and measured 2 feet 6 inches parallel chamber by 2 feet at right angles to it.
The floor of this "shelf" is on a level 4 feet 4 inches above the floor of the main chamber, and the height of the clear space is about 1 foot 9 inches. A similar pocket was also found to the behind two of the stones in the left-hand recess. In each of the inner corners of the right-hand recess there is a block of stone about 8 inches square and 1 foot 3 inches high, set on end.
On the western side of this carn, half buried in the turf, a slab is lying which may possibly have been intended for the construction but left over. It is 1 foot 3 inches thick, 7 feet 3 inches long, 3 feet broad at one end, 5 feet broad at the other.