The large ruin, which forms the principal attraction of this place, is situated about seven hundred paces to the south of this tomb. It is called by the natives Tauk Kesra (the Arch of Kesra). It is composed of two wings and one large central hall, extending all the depth of the building. Its front is nearly perfect; being two hundred and sixty feet in length, and upwards of one hundred feet in height. Of this front the great arched hall occupies the centre; its entrance being of an equal height and breadth with the hall itself. The arch is thus about ninety feet in breadth, and rising above the general line of the front, is at least one hundred and twenty feet high, while its depth is at least equal to its height. "The wings leading out on each side of the central arch," continues Mr. Buckingham, "to extend to the front of the building, are now merely thick walls; but these had originally apartments behind them, as may be seen from undoubted marks that remain, as well as two side doors leading from them into the great central hall." The walls which form these wings in the line of the front were built on the inclined slope, being in thickness about twenty feet at the base; but only ten at the summit. The masonry is altogether of burnt bricks, of the size, form, and composition of those seen in the ruins of Babylon; but none of them have any writing or impression of any kind. The cement is white lime, and the layers are much thicker than is seen in any of the burnt brick edifices at Babylon; approaching nearer to the style of the Greek and Roman masonry found among the ruins of Alexandria, where the layers of lime are almost as thick as the bricks themselves. At Babylon the cement is scarcely perceptible. The symmetry of the work bears considerable resemblance, however, both to the Birs and the fine fragments of brick-masonry of the age of the Caliphs, still remaining at Bagdad. The wings, though not perfectly uniform, are similar in their general construction; "but the great extent of the whole front," says our accomplished traveller, "with the broad and lofty arch of its centre, and the profusion of recesses and pilasters on each side, must have produced an imposing appearance, when the edifice was perfect; more particularly if the front was once coated, as tradition states it to have been, with white marble; a material of too much value to remain long in its place after the desertion of the city." The arches of the building are described to be all of a Roman form, and the architecture of the Roman style, though with less purity of taste; the pilasters having neither capital nor pedestal, and a pyramidal termination is given to some of the long narrow niches of the front.