History of the Peloponnesian War

The Syracusians the same summer, when they heard that the Athenians had horsemen sent to them from Athens and that they were ready now to come against them, conceiving that if the Athenians gat not Epipolae, a rocky ground and lying just against the city, they would not be able, though masters of the field, to take in the city with a wall, intended therefore, lest the enemy should come secretly up, to keep the passages by which there was access unto it with a guard.

For the rest of the place is to the outside high and steep, falling to the city by degrees, and on the inside wholly subject to the eye. And it is called by the Syracusians Epipolae, because it lieth above the level of the rest.