This range of mountains, which extends from Leucas and the sea on the west, through Aetolia to the opposite sea on the east, is so closely covered with thickets and craggy rocks, that, not to speak of an army, even persons lightly equipped for travelling can with difficulty find paths through which they can pass.

The hills at the eastern extremity are called Oeta, and the highest of them Callidromus; in a valley, at the foot of which, reaching to the Malian bay, is a passage not broader than sixty paces.
This is the only military road by which an army can be led, even if it should not be opposed.

The place is therefore called Pylae, the gate; and by some, on account of a warm spring, rising just at the entrance of it, Thermopylae.

It is rendered famous by the memorable battle of the Lacedaemonians against the Persians, and by their still more glorious death.
16.

With a very inferior portion of spirit, Antiochus now pitched his camp within the enclosures of this pass, the difficulties of which he increased by raising fortifications; and when he had completely strengthened every part with a double rampart and trench, and, wherever it seemed requisite, with a wall formed of the stones which lay scattered about in abundance, being very confident that the Roman army would never attempt to force a passage there, he sent away one half of the four thousand Aetolians, the number that had joined him, to garrison Heraclea, which stood opposite the entrance of the defile, and the other half to Hypata; for he concluded, that the consul would undoubtedly attack Heraclea, and he received accounts from many hands, that all the districts round Hypata were being laid waste.