Cruachan, or Rathcrogan, is situated five miles west from Carrick-on-Shannon, and consists, according to Petrie, of a circular stone ditch,[242] now nearly obliterated, 300 feet in diameter. Within this "are small circular mounds, which, when examined, are found to cover rude sepulchral chambers, formed of stone, without cement of any kind, and containing unburnt bones." The monument of Dathi (428 A.D.), which is a small circular mound with a pillar-stone of Red Sandstone, is situated outside the enclosure, at a short distance to the east, and may be identified from the following notice of it by the celebrated antiquary Duald Mac Firbis. "The body of Dathi was brought to Cruachan, and was interred at Relig na Riogh, where most of the kings of the race of Heremon were buried, and where to this date the Red Stone pillar remains on a stone monument over his grave, near Rath Cruachan, to this time (1666)."[243] Here, therefore, we have the familiar 300-foot circle, with the external burial, as at Arbor Low, and external stone monument as at Salkeld and elsewhere. The chief distinction between this and our English battle-circles seems to be the number of cairns, each containing a chamber, which crowd the circle at Rath Crogan, and it is possible that if these were opened with great care, a succession might be discovered among them; but at present we know little or nothing of their contents. At present there are only two names that we can identify with certainty as those of persons buried here. Queen Meave, who, as before mentioned, was transferred from Fert Meave--or Meave's Grave, her first burying-place, to this Rath, about the end of the first century, and Dathi, at the beginning of the fifth. Whether any other persons were interred here before the first-named queen seems doubtful. From the context, it seems as if her being buried in her own Rath had led to its being consecrated to funereal rites, and continuing to be so used till Christianity induced men to seek burying-places elsewhere than in the cemeteries of the idolaters. * * * * * By far the best known, as well as the most interesting, of Irish cemeteries is that which extends for about two miles east and west on the northern bank of the Boyne, about five miles from Drogheda. Within this space there remain even now some seventeen sepulchral barrows, three of which are pre-eminent.[244] They are now known by the names of Knowth for the most westward one, Dowth for that to the east, and about halfway between these two, that known as New Grange. In front of the latter, but lower down nearer the river, is a smaller one, still popularly known as that of the Dagdha, and others bear names with more or less certainty; but no systematic exploration of the group has yet been made, so that we are very much in the dark as to their succession, or who the kings or nobles may be that lie buried within their masses.