In 480 there appears to have been deep water close to the road, for Herodotus in his account of the final attack of the Persians on the pass speaks of many of them falling into the sea and perishing (vii. 223). The truth of this detail is strongly supported by Pausanias’ description (x. 21, 4) of how the Athenian fleet two centuries later attacked the flank of the Gauls when they were assailing the middle gate. I am inclined to think that the deep water must have been at the base of the two mounds which stand at the east end of it. The marshes spoken of (vii. 176) would be those formed at the point where the hot springs reached the shore, probably several hundred yards west of where they now come down to the aqueduct. The breadth of half a plethron, or fifty feet, is evidently to be applied to that part of the pass which extended from the first mound westward in the direction of the modern baths (_vide_ Plan). South of this the mountain side rises at a very steep angle, and, apart from its steepness, is practically untraversable, owing to the nature of the rock-strewn slope, and the thick brushwood which covers it. ◆The Phocian Wall.◆ The question as to the exact position of the Phocian wall is a somewhat difficult one to solve. At the same time, I see strong reason to think that the existing remains of wall foundations on the neck by which the first mound is attached to the mountain side are relics of a wall which, if not identical with, is identical in site with the one which the Phocians built. Of this wall I noted the following details. The general line of it is distinct. It can be traced seventy or eighty yards south from the summit of the mound along the neck of the ridge, and it seems to have been carried down the north slope of the mound towards what is now the sulphur deposit but which was in former times the sea. The detail of its plan is somewhat indistinct, largely owing to its having been very much cut about in constructing rifle pits for the expected defence of the pass in the recent war with Turkey. It seems to have been planned as a series of angle bastions projecting westwards, connected by curtains a few yards long. It is from three to three feet six inches thick, and formed of stones, some of which are roughly squared, and have an average dimension of fifteen inches by ten.