Babylon surpassed all ancient cities in size and magnificence. Its walls were forty miles in circumference. This extent of wall probably included Borsippa, or "Babylon the Second," on the right bank of the river. Babylon proper was mainly on the left. Within the walls were inclosed gardens, orchards, and fields: the space was only filled in part by buildings; but the whole area was laid out with straight streets intersecting one another at right angles, like the streets of Philadelphia. The wall was pierced by a hundred gates, probably twenty-five in each face. The Euphrates, lined with quays on both sides, and spanned with drawbridges, ran through the town, dividing it into two nearly equal parts. The city was protected without by a deep and wide moat. The wall was at least seventy or eighty feet in height, and of vast and unusual thickness. On the summit were two hundred and fifty towers, placed along the outer and inner edges, opposite to one another, but so far apart, according to Herodotus, that there was room for a four-horse chariot to pass between. The temple of _Bel_ was in a square inclosure, about a quarter of a mile both in length and breadth. The tower of the temple was ascended on the outside by an inclined plane carried around the four sides. An exaggerated statement of _Strabo_ makes its height six hundred and six feet. Possibly, this represents the length of the inclined plane. In the shrine on the top were a golden table and a couch; according to _Diodorus_, before the Persian conquest there were colossal golden images of three divinities, with two golden lions, and two enormous serpents of silver. It is thought that Herodotus may have described the splendid temple of _Nebo_ (now _Birs Nimrûd_), and have mistaken it, by reason of its enormous ruins, for the temple of _Bel_, which it rivaled in magnificence. The great palace is represented to have been larger than the temple of Bel, the outermost of its three inclosing walls being three miles in circumference. Its exterior was of baked brick. The "Hanging Gardens" was a structure built on a square, consisting of stages or stories, one above another, each supported by arches, and covered on the top, at the height of at least seventy-five feet, with a great mass of earth in which grew flowers and shrubs, and even large trees. The ascent to the top was by steps. On the way up were stately and elegant apartments. The smaller palace was on the other side of the river.