THERMOPYLÆ, (anc. geog.); a narrow pass or defile, between the walls of the Sinus Maliacus; on the east and steep mountains, reaching to Oeta, made dreadful by impassable woods; on the west, leading from Thessaly to Locri and Bœotia. These mountains divide Greece in the middle, in the same manner as the Apennine does Italy; forming one continued ridge from Leucate on the west to the sea on the east, with thickets and rocks interpersed; that persons even prepared for travelling, much less an army encumbered with baggage, cannot easily find a commodious passage. In the valley verging towards the Sinus Maliacus, the road is only sixty paces broad; the only military way for an army to pass, if not obstructed by an enemy; and therefore the place is called Pyla, and by others, on account of its hot water, Thermopyle. Ennobled by the brave stand made by Leonidas and three hundred Spartans against the whole army of Persia; and by the bold resolution of blind Euthycus, choosing rather to fall there in fight, than return to Sparta, and escape the common danger. Famous also for the Amphictiones, the common council or states general of Greece, assembling there twice a year, spring and autumn. For an account of the battle of Thermopylæ at which Leonidas with a handful of men engaged the Persian army, see SPARTA.