Histories
Herodotus
Herodotus. Godley, Alfred Denis, translator. Cambridge, MA; London: Harvard University Press; William Heinemann, Ltd., 1920-1925 (printing).
Further, at the end of each road there was a gate in the riverside fence, one gate for each alley; these gates also were of bronze, and these too opened on the river.
These walls are the city's outer armor; within them there is another encircling wall, nearly as strong as the other, but narrower.