The eastern frontier was furnished with a rampart protected by a wide moat, following, between Jibbara and Nipur, the contours of a low-lying district which could be readily flooded. The western boundary was already protected by the Pallakottas, and the lakes or marshes of Bahr-i-Nejif: Nebuchadrezzar multiplied the number of the dikes, and so arranged them that the whole country between the suburbs of Borsippa and Babylon could be inundated at will. Babylon itself formed as it were the citadel in the midst of these enormous outlying fortifications, and the engineers both of Nabopo-lassar and of his son expended all the resources of their art on rendering it impregnable. A triple rampart surrounded it and united it to Borsippa, built on the model of those whose outline is so frequently found on the lowest tier of an Assyrian bas-relief. [Illustration: 457.jpg PROBABLE SECTION OF THE TRIPLE WALL OF BABYLON] Reproduced by Faucher-Gudin, from the restoration by Dieulafoy. A moat of great width, with banks of masonry, communicating with the Euphrates, washed the foot of the outer wall, which retained the traditional name of Imgur-bel: behind this wall rose Nimitti-bel, the true city wall, to a height of more than ninety feet above the level of the plain, appearing from a distance, with its battlements and towers, more like a mountain chain than a rampart built by the hand of man; finally, behind Nimitti-bel ran a platform on the same level as the curtain of Imgur-bel, forming a last barrier behind which the garrison could rally before finally owning itself defeated and surrendering the city. Large square towers rose at intervals along the face of the walls, to the height of some eighteen feet above the battlements: a hundred gates fitted with bronze-plated doors, which could be securely shut at need, gave access to the city.* * The description of the fortifications of the city is furnished by Herodotus, who himself saw them still partially standing; the account of their construction has been given by Nebuchadrezzar himself, in the _East India Company's Inscription_. The space within the walls was by no means completely covered by houses, but contained gardens, farms, fields, and, here and there, the ruins of deserted buildings. As in older Babylon, the city proper clustered round the temple of Merodach, with its narrow winding streets, its crowded bazaars, its noisy and dirty squares, its hostelries and warehouses of foreign merchandise. [Illustration: 458.jpg FRAGMENT OF A BABYLONIAN BAS-RELIEF] Drawn by Faucher-Gudin, from a sketch in Layard.