Here the bulk of what has been uncovered consists of suite after suite of small rooms, usually in sets of four or six, and probably forming the apartments of the multitudinous Court officials. Also, there are long ranges of vaulted cellars and store-rooms; where in some cases the arches of the roof and door-way have survived for a testimony that the Chaldaeans were well acquainted with the principle of the vault. The great feature of the Palace, however, is the Hall of Audience--the scene, in all probability, of Belshazzar's feast--which happens to be the only part where the walls stand up above the original ground level. This is a grand hall indeed, measuring 200 feet by 80, and therefore as large as the nave of many a cathedral; and one can still trace opposite the doorway the apse that was the site of the throne. It is surprising to find that Chaldaean builders dared throw a vault across such a space as this; yet the total absence of the bases of any internal columns (such as would be needed to support a timber roof), unites with the extraordinary thickness of the side wall to convince the German excavators that such was actually the case. A "wagon vault" of such a span would be no mean feat even now; though the Sassanid builders did not fear it, as may be seen in the still existing "Arch of Chosroës" on the site of ancient Ctesiphon. This great vault, shown in our illustration, may still be seen standing near Baghdad, and was in all probability a replica of Nebuchadnezzar's hall. To the north of the Palace was the deep dry moat which bounded both the city and the royal quarter; and which the Processional Way crossed, most probably by a bridge, though of this no evidence remains. The German excavators consider that this moat, or at all events some part of it, was the "den of lions" of the King of Babylon. There is evidence in parallel instances that such was the case elsewhere. Of course the great temples of Bel-Merodach, Ishtar, and other gods, form a feature of the city, and have been most carefully excavated. They were constructed on a plan that seems strange to the Western; for they have no precinct, or have lost what they had, and the houses of the poorest quarter of the town actually abutted on the walls of the holiest of them.