From Doris the invaders passed into Phocis. There is no natural boundary between the two plains; and the records of the history of this region, dim though they are, point to a frequent shifting of the frontier. The Phocians had one retreat to which they could always resort; and, before the invasion was on them, they took to the heights of Parnassus, whose great humped mass rises more than seven thousand five hundred feet above the plain. It was evidently the accustomed refuge of the race. They had adopted the same plan at the time of the undated Thessalian attack on their country. ◆H. viii. 32.◆ The actual place of refuge on this occasion was Tithorea, not apparently at this time the city which it became later, but a strong natural position, which could be easily defended. #PERSIAN RAID ON DELPHI.# Many of them, however, had made their way to Amphissa, at the head of the Krissæan plain, not far from Delphi, passing thither, doubtless, through Dorian territory by way of the direct pass through the mountains from Kytinion to Amphissa, which is the southern continuation of the Thermopylæ-Delphi route by way of the Asopos ravine. The destruction which the Persians wrought in Phocis was complete in so far as the plain was concerned. Its cities were plundered and destroyed; and the great oracular shrine at Abæ, close to Hyampolis, was robbed of its treasures and burnt to the ground. At Parapotamii the plunderers from the plain would meet with the main force, which must have come round by the Atalanta route, to which the destruction of Abæ and Hyampolis may presumably be attributed.[149] It was from this point that a flying column was sent to attack Delphi, while the mass of the army held on its way through Bœotia. The route followed in the march to Delphi must have been the celebrated “divided way” (σχίστη ὁδός), made famous in the myth of Œdipus, ◆H. viii. 35.◆ for Herodotus mentions that they passed by Daulis and left Parnassus on their right. The object of this expedition was to seize the immensely valuable offerings at the great shrine, and especially those of Crœsus, the Lydian king. The element of the supernatural plays so large a part in the tale of the adventures of this band of plunderers, that it is impossible to say with certainty what really happened. Some catastrophe overtook them in the immediate neighbourhood of Delphi itself; and the very remarkable physical characteristics of the neighbourhood of the town, together with the story in Herodotus divested of its supernatural element, render it possible to hazard a conjecture as to what was the actual nature of this catastrophe.