O'Donovan says also in the same unpublished letters that "The antiquary may draw his own conclusion from the non-existence of a dun on the hill of Allen at this day. It is possible that there were forts on it a thousand years ago, and that the progress of cultivation has effaced them; but it is strange that these alone should disappear, while those of Tara, Emania, Aileach, Naas, Maistean, and Raoirean remain in good preservation.... It is curious to remark that all the monuments mentioned in the _Dinnseanchus_ and the authentic annals still exist, while no trace is to be found of Finn Mac Cool's palace on the hill of Allowin (Allen).... If he had such a palace as this on Aillinn, near Kilcullen, on his hill of Allowin, it would not disappear, because the labour of levelling it would be so great that no agriculturist would undertake to level it." It would seem as if the two hills, Aillinn, or Knock Aillinn as it is now called, and Allen got confounded, and at an early date too. Allowing liberally for exaggeration and discounting tradition, one has to believe in the extent of Finn's house or palace, however rude and barbaric its arrangements may have been. He was the most powerful man in Ireland, more powerful even than the chief king. The fame of his household was spread abroad, not only over all Ireland, but all Scotland. This we know by the publication of the poems collected in the Highlands by the Dean of Lismore in the sixteenth century, and translated by the late Mr T. M'Lauchlan, and also from a host of other poems. They abound with allusions to Finn and his house and household, as does almost all the folk-lore of the Celtic-Scotch. One thing seems certain, that neither Finn nor his house or palace were myths; his house must have existed, and, like all places of its kind in the days when it existed, it must have been surrounded with an earthen rampart no less high than that to be seen on Knock Aillinn. But no vestige of house or rampart can be traced on the hill of Allen. A still greater difficulty meets one in the size of the summit of the hill. It is not much over half an Irish acre in extent, and where would there be room on such a limited space for the vast household of Finn? His residence was known from far-back times as "Almhuin riogha leathan mór Laighean," the kingly, great-broad Allen of Leinster; but no _dun_ or habitation situated on the narrow space on the top of the hill of Allen could be "great-broad;" but the existing remains on Knock Aillinn would suit the description almost exactly. We may be sure that if any man in Ireland in those days had a big house, it was Finn. The names Allen and Aillinn are so much alike, and both hills are so comparatively near each other, and both seem to have been abandoned as strongholds at such an early date, that confusion of one with the other could easily have taken place; besides, Finn's name does appear to be, in some measure at least, associated with Knock Aillinn.