History of the Peloponnesian War

On that day the Athenians advanced about forty stades, and then halted for the night on a hill. The day following, they commenced their march at an early hour, and having advanced about twenty stades, descended into a level district, and there encamped, wishing to procure some eatables from the houses, (for the place was inhabited,) and to carry on with them water from it, since for many stades before them, in the direction they were to go, it was not plentiful.

The Syracusans, in the mean time, had gone on before, and were blocking up the pass in advance of them. For there was there a steep hill, with a precipitous ravine on either side of it, called the Acraeum Lepas.