That at Knowth has never been carefully measured, nor, so far as I know, even described in modern times. At a guess, it is a mound 200 feet in diameter, and 50 to 60 feet in height, with a flat top not less than 100 feet across. It is entirely composed of small loose stones, which have been extensively utilized for road making and farm buildings, so that the mound has now a very dilapidated appearance, which makes it difficult to ascertain its original form; and so far as is known, its interior has not been accessible in modern times. Petrie identifies it (p. 103) with "the cave of Cnodhba, which was searched by the Danes on an occasion (A.D. 862), when the three kings, Amlaff, Imar, and Auisle, were plundering the territories of Flann, the son of Conaing. If this is so, its entrance ought not to be difficult to find, but the prospect of the explorers being rewarded by any treasure or object of value is very small indeed. [Illustration: 63. View of Mound at New Grange. From a drawing by Colonel Forbes Leslie.] Less than a mile from this one is the larger and more celebrated mound of New Grange. It is almost certainly one of the three plundered by the Danes 1009 years ago. No description of it has anywhere been discovered, prior to the time when Mr. Llwyd, the keeper of the Ashmolean Museum at Oxford, mentioned it in a letter dated Sligo, 1699.[245] He describes the entrance, the passage, and the side chapels, and the three basins as existing then exactly as they do now, and does not allude to the discovery of the entrance as being at all of recent occurrence, though Sir Thomas Molyneux, in 1725, says it was found apparently not long before he wrote, in accidently removing some stones.[246] The first really detailed account, however, is that of Governor Pownall, in the second volume of the 'Archæologia' (1770). He employed a local surveyor of the name of Bouie to measure it for him, but either he must have been a bungler, or the engraver has misunderstood his drawings, for it is almost impossible to make out the form and dimensions of the mound from the plates published. In the 100 years that have elapsed since his survey was made, the process of destruction has been going on rapidly, and it would now require both skill and patience to restore the monument to its previous dimensions. Meanwhile the accompanying cuts, partly from Mr. Bouie's plates, partly from personal observations, may be sufficient for purposes of illustration, but they are far from pretending to be perfectly accurate, or such as one would like to see of so important a monument.