History of the Peloponnesian War

During the same summer the Syracusans, on learning that the Athenians had received their cavalry and that they were about to march against them immediately, thinking that unless the Athenians should get possession of Epipolae, a precipitous place lying directly above the city, they themselves, even if they were defeated in battle, could not easily be walled in, determined to guard the approaches to it, in order to prevent the enemy from ascending secretly by that way, since they could not possibly do so by any other road.

For at all other points the place overhangs the city and slopes right down to it, the whole height being visible from it; and it is called Epipolae by the Syracusans because it lies as an upper surface above the rest of the country.