early as 3000 years before Christ; yet it must be the lineal descendant of a rude-chambered tumulus or cairn, with external access to the chambers, and it seems difficult to calculate how many thousands of years it must have required before such rude sepulchres as those our ancestors erected--many probably after the Christian era--could have been elaborated into the most perfect and most gigantic specimens of masonry which the world has yet seen. The phenomenon of anything so perfect as the Pyramids starting up at once, absolutely without any previous examples being known, is so unique[42] in the world's history, that it is impossible to form any conjecture how long before this period the Egyptians tried to protect their bodies from decay during the probationary 3000 years.[43] [Illustration: 1. Section of Tomb of Alyattes. From Spiegelthal. No scale.] Outside Egypt the oldest tumulus we know of, with an absolutely authentic date, is that which Alyattes, the father of Crœsus, king of Lydia, erected for his own resting-place before the year 561 B.C. It was described by Herodotus,[44] and has of late years been thoroughly explored by Dr. Olfers.[45] Its dimensions are very considerable, and very nearly those given by the father of history. It is 1180 feet in diameter, or about twice as much as Silbury Hill, and 200 feet in height, as against 130 of that boasted monument. The upper part, like many of our own mounds, is composed of alternate layers of clay, loam, and a kind of rubble concrete. These support a mass of brickwork, surmounted by a platform of masonry; on this still lies one of Steles, described by Herodotus, and another of the smaller ones was found close by. [Illustration: 2. Elevation of Tumulus at Tantalais. From Texier's 'Asie Mineure.' 100 ft. to 1 in.] [Illustration: 3. Plan and Section of Chamber in Tumulus at Tantalais.] There is another group of tombs, called those of Tantalais, found near Smyrna, which are considerably older than those of Sardis, though their date cannot be fixed with such certainty as that last described. Still there seems no good reason for doubting that the one here represented may be as old as the eleventh or twelfth century B.C., nor does it seem reasonable to doubt but these tumuli which still stand on the plain of Troy do cover the remains of the heroes who perished in that remarkable siege.[46] A still more interesting group, however, is that at Mycenæ, known as the tombs or treasuries of the Atridæ, and described as such by Pausanias.[47] The principal, or at least the best preserved of these, is a circular chamber, 48 feet 6 inches in diameter, covered by a horizontal vault, and having a sepulchral chamber on one side. Dodwell discovered three others of the five mentioned by Pausanias,[48] and he also explored the sepulchre of Minyas at Orchomenos, which had a diameter of 65 feet. [Illustration: 4. Section and Plan of Tomb of Atreus at Mycenæ. Scale of plan 100 ft. to 1 in.]