Among the trees between the mound of Dowth and the mansion are two smaller tumuli. One of these is open from the top; it contains a corbel-roofed chamber 10 feet in diameter and 8 feet high; round it are five cells constructed of small flags set upright. A little to the east of the house is a fine specimen of the ancient military encampment or rath, one of the largest in Ireland. * * * * * _Tumulus at Knowth._--The other great tumulus (Knowth) of the Boyne group has probably never been entered since the time, as the Annalists tell us, it was plundered and doubtlessly much injured by the Danes. It is nearly 700 feet in circumference, and between 40 and 50 feet in height. For many years it has served as a convenient quarry for builders of houses and repairers of roads. That it could be explored at little cost is certain, as, owing to the denudation it has suffered, the passage or gallery leading to its chamber has, in part, been laid bare. Its circle or circles are not altogether obliterated; and here and there some portions remain which show that the work, though less massive than that of Newgrange, was at least as striking as anything to be found in Dowth, or in connection with the remains at Loughcrew, or others occurring in the western districts of Ireland. Among the objects found about the tumuli Lhwyd mentions a gold coin of Valentinian, said to have been discovered on the top of Newgrange; Molyneux mentions a similar coin, and one of Theodosius, as being found outside the cairn. A gold chain, two finger rings, and two gold torcs were found in 1842 close to the entrance of Newgrange; and on further search a denarius of Geta and two small brass, but defaced, coins were also found. Too much caution cannot be used in considering these as evidence in determining the date of the tumuli. A bronze pin, a ring pin, and a small iron weapon were found in the chamber discovered in Dowth in 1885. If, as seems certain, this chamber and passage are of much later date than the tumulus itself, the presence of these objects is easily accounted for. A discussion of the evidence upon which expert opinion is based, as to the date of these monuments, is outside the province of this book. It takes into consideration the character of the architecture, the nature of the ornamentation, and the objects found. Weighing these, the Boyne tumuli are assigned to the Early Bronze Period, and Newgrange is considered the oldest of the group. * * * * *