Cairn D is the largest and most important monument of the group, being 180 feet in diameter, and though it is very much dilapidated, the circle of fifty-four stones which originally surrounded it can still be traced. On its eastern side the stones curve inwards for about twelve paces, in the form universal in these cairns; but though the explorers set to work industriously to follow out what they considered a sure "find," they could not penetrate the mound. The stones fell in upon them so fast, and the risk they ran was so great, that they were forced to abandon the idea of tunnelling, and though a large body of men worked assiduously for a fortnight trying to work down from above, they failed to penetrate to the central or any other chambers. It still, therefore, remains a mystery if there is a blind tope, like many in India, or whether its secret still remains to reward some more fortunate set of explorers. If it has no central chamber, the curving inwards of its outer circle of stones is a curious instance of adherence to a sacred form. The other monuments on the hill do not present any features worth enumerating in a general summary like the present, though they would be most interesting in a monograph. Though differing greatly in size and in richness of ornamentation, they all belong to one class, and apparently to one age. For our present purpose one of the most interesting peculiarities is that, like the group on the banks of the Boyne, this is essentially a cemetery. There are no circles, no alignments, no dolmens, no rude stone monuments, in fact. All are carefully built, and all more or less ornamented; and there is a gradation and progression throughout the whole series widely different in this respect from the simplicity and rudeness of the English monuments described in the last chapter. * * * * * It now only remains to try to ascertain who those were who were buried in these tumuli, and when they were laid there to their rest. So far as the evidence at present stands it hardly seems to me to admit of doubt but that this is the cemetery of Talten, so celebrated in Irish legend and poetry:-- "The host of Great Meath are buried In the middle of the Lordly Brugh; The Great Ultonians used to bury At Talten with pomp. "The true Ultonians, before Conchobar, Were ever buried at Talten, Until the death of that triumphant man, Through which they lost their glory."[253]