History of the Peloponnesian War

And they worked with still greater earnestness at the fort in Eetionia. Now the object of the fort, as Theramenes and his party maintained, was this; not that they might avoid admitting the army at Samos into the Piraeus, should they attempt to sail in by force; but rather that they might admit the enemy, whenever they pleased, both with ships and troops. For Eetionia is a mole of the Piraeus, and the entrance into the harbour is straight by it.

It was being fortified therefore in such a manner, in connexion with the wall previously existing on the land side, that, with only a few men posted in it, it would command the entrance. For in the very tower standing on one of the two sides, at the mouth of the harbour, which was narrow, was the termination both of the original wall on the land side, and of the new and inner one which was being built on the side of the sea.

They also built a portico, which was very large and in immediate connexion with this wall in the Piraeus; of which they themselves had the command, and in which they compelled all to deposit both what corn they had before and what was now brought in, and to take it out thence when they sold it.