_Mount Venus Cromlech._--This monument, situated at Woodtown, about two and a half miles from Rathfarnham, a suburb of Dublin, is no longer perfect. Its table, which may have slipped from its original position, is at present supported by a single stone about 7½ feet in height, and of considerable massiveness. The greatest measurement of the covering stone is 23 feet; it is 12 feet in breadth, and 5 feet in thickness. It is supported at the north-west corner by an upright stone, forming with it an angle of 45°. Several of the former supporting stones would seem to have been removed, and others have evidently been broken. The rock is granite, of a very hard, close, and durable description. It seems to have weathered but little, as all the remaining stones present angles of considerable sharpness. Du Noyer was of opinion that this cromlech was of what he styled the ‘earth-fast’ class, and that the roof had always in part rested upon the ground. In this supposition O’Neill, no mean authority on such matters, did not by any means coincide. The weight of the covering stone is estimated at 42 tons. So great a pressure might well cause some of the weaker supporters to give way, in which case the pile would very probably assume its present appearance. It is not in the least likely that this tomb had at any time been covered by a tumulus or cairn. Mr. Borlase considers it ‘one of the most magnificent megalithic monuments in the world.’ [Illustration: Shanganagh Cromlech.] * * * * * _Shanganagh Cromlech._--At Shanganagh, half a mile to the east of the hamlet of Loughlinstown, may be seen a fine specimen of what may be styled, as regards size, a cromlech of the second class. It is supported upon four stones, and presents no appearance of having been enveloped in a mound of any description. Like nearly every one of its kindred remains in the County Dublin, it is formed of granite blocks. The covering stone measures 9 feet in length by 7 feet at its greatest breadth; it is 3½ feet in its extreme thickness; and its highest portion is at present slightly over 9 feet above the ground; the weight is about 12 tons. The chamber would seem to extend east and west. The cromlech may be easily visited from Killiney railway station. * * * * *