History of the Peloponnesian War

Nicias also determined to fortify Plemmyrium, a promontory over against the city, which juts out and narrows the mouth of the great harbor. He thought that the fortification of this place would make it easier to bring in supplies, as they would be able to carry on their blockade from a less distance, near to the port occupied by the Syracusans; instead of being obliged, upon every movement of the enemy's navy, to put out against them from the bottom of the great harbor. Besides this, he now began to pay more attention to the war by sea, seeing that the coming of Gylippus had diminished their hopes by land.

Accordingly, he conveyed over his ships and some troops, and built three forts in which he placed most of his baggage, and moored there for the future the larger craft and men-of-war.

This was the first and chief occasion of the losses which the crews experienced. The water which they used was scarce and had to be fetched from far, and the sailors could not go out for firewood without being cut off by the Syracusan horse, who were masters of the country; a third of the enemy's cavalry being stationed at the little town of Olympieum, to prevent plundering incursions on the part of the Athenians at Plemmyrium.

Meanwhile Nicias learned that the rest of the Corinthian fleet was approaching, and sent twenty ships to watch for them, with orders to be on the look-out for them about Locris and Rhegium and the approach to Sicily.