At a distance of twenty-five miles nearly due west from Brugh na Boinn, and two miles south-east from Oldcastle, is a range of hills, called on the Ordnance map Slieve na Calliagh--the hags' or witches' hill. It is upwards of 200 feet above the level of the sea, and the most conspicuous elevation in that part of the country. On the ridge of this range, which is about two miles in extent, are situated from twenty-five to thirty cairns, some of considerable size, being 120 to 180 feet in diameter; others are much smaller, and some so nearly obliterated that their dimensions can hardly be now ascertained. Till seven or eight years ago this cemetery was entirely unknown to Irish antiquaries, and the positions of the cairns were hardly even indicated in the Ordnance Survey; but in 1863 they attracted the attention of Mr. Eugene Conwell, of Trim. In the years 1867-8 he was enabled, with the assistance and co-operation of the late Mr. Naper, of Lough Crew, the proprietor of the soil, to excavate and explore the whole of them. A brief account of the results which he obtained was submitted to the Royal Irish Academy in 1868, and afterwards printed by him for private circulation in 1868; but the greater work, with plans and drawings, in which he intends fully to illustrate the whole, is still in abeyance, owing to want of encouragement. When completed it will be one of the most valuable contributions to our archæological knowledge that we have received of late years. Meanwhile the following meagre particulars are derived from Mr Conwell's pamphlet and the information I picked up during a personal visit which I made to the spot in his company in the Autumn of last year. The illustrations are all from his drawings. [Illustration: 72. Cairn T, at Lough Crew.--From a plan by E. Conwell.] One of the most perfect of these tumuli is that distinguished by Mr. Conwell as Cairn T (woodcut No. 72). It stands on the highest point of the hill, and is consequently the most conspicuous. It is a truncated cone, 116 feet in diameter at base, and with a sloping side, between 60 and 70 feet in length. Around its base are thirty-seven stones, laid on edge, and varying from 6 to 12 feet in length. They are not detached, as at New Grange, but form a retaining wall to the mound. On the north, and set about 4 feet back from the circle, is a large stone, 10 feet long by 6 high, and 2 feet thick, weighing consequently above 10 tons. The upper part is fashioned as a rude seat, from which it derives its name of the Hag's Chair (woodcut No. 73), and there can be little doubt but that it was intended as a seat or throne; but whether by the king who erected the sepulchre, or for what purpose, it is difficult now to say. [Illustration: 73. The Hag's Chair, Lough Crew.--From a drawing by E. Conwell.]