History of the Peloponnesian War

At every ten battlements stood a great tower of a just breadth to comprehend both walls and reach from the outmost to the inmost front of the whole, so that there was no passage by the side of a tower but through the midst of it.

And such nights as there happened any storm of rain, they used to quit the battlements of the wall and to watch under the towers, as being not far asunder and covered beside overhead. Such was the form of the wall wherein the Peloponnesians kept their watch.