Flavius Josephus, The Wars of the Jews
William Whiston, A.M., Ed.

[79] As for what is within the camp, it is set apart for tents, but the outward circumference hath the resemblance to a wall, and is adorned with towers at equal distances, where between the towers stand the engines for throwing arrows and darts, and for slinging stones, and where they lay all other engines that can annoy the enemy, all ready for their several operations. They also erect four gates, one at every side of the circumference, and those large enough for the entrance of the beasts, and wide enough for making excursions, if occasion should require. They divide the camp within into streets, very conveniently, and place the tents of the commanders in the middle; but in the very midst of all is the general's own tent, in the nature of a temple, insomuch, that it appears to be a city built on the sudden, with its market-place, and place for handicraft trades, and with seats for the officers superior and inferior, where, if any differences arise, their causes are heard and determined. The camp, and all that is in it, is encompassed with a wall round about, and that sooner than one would imagine, and this by the multitude and the skill of the laborers; and, if occasion require, a trench is drawn round the whole, whose depth is four cubits, and its breadth equal.