together by mortar of asphalt; according to Xenophon,[693] who saw parts of it still standing, the breadth was 20 feet and the height 100 feet. The native land, the centre of the kingdom, was thus protected; and even when it was lost, in spite of the protection of the two streams, the canals, and the long wall, the metropolis was intended to present impregnable fortresses to the enemy. Babylon had no doubt suffered the most severe wounds in all the land of Chaldæa through the capture by Assurbanipal. Berosus says: "Nebuchadnezzar restored the old city, and also built a new one, and that the besieger might not enter the city by averting the stream, he surrounded the inner city as well as the outer with three walls, one of burnt bricks, the other two of unburnt bricks and bitumen, and thus he fortified it in a very striking manner, and adorned the gates with great splendour."[694] Herodotus, who saw the city more than one hundred years after the death of Nebuchadnezzar, when it had been four times captured by Cyrus, Darius, and Xerxes, describes it thus: "The city is situated in a wide plain, and forms a square of 120 stades on each side, so that the whole circuit reaches 480 stades. It is divided into two parts, and the river Euphrates flows through the middle. It is surrounded by a broad and deep trench, which is always filled with water. The soil taken from this trench was made into bricks, and burnt; and these bricks were applied, first to lining the trench and then to building the wall. The wall is 50 Babylonian cubits in thickness and 200 cubits in height. The bricks are held together by bitumen-mortar, and at every thirtieth course they are separated by a layer of reeds. On the wall are houses of a single chamber, built on either side opposite each other, and yet sufficient space is left between them for a chariot and four to pass. In the wall are one hundred gates, all of brass, with brazen lintels and side-posts. The wall has wings which run along the river on either side, and the banks are cased with masonry of burnt bricks. The city itself is filled with houses of three and four stories, through which are straight streets--both those which lead to the river and the rest. Those which run down to the river have each a brazen gate in the masonry on the river, through which you pass on steps of burnt brick into the water.[695] And within this wall, which is as it were the corslet of the city, is another wall, not much inferior in strength to the other, but less in extent. Of the two parts of the city the centre of the one is occupied by the royal citadel, the centre of the other by the temple of Belus with the gates of brass."[696] In another passage Herodotus gives the names of some of the gates of Babylon; he mentions the gate of Belus, the gate of Semiramis, the gate of Ninus, the gate of the Chaldæans, and the gate of the Cissians.