Four days' march, the first of only sixty stadia, or about seven miles,[14] brought the Greeks to the high mountains of Kurdistan, which, meeting the Tigris, shut out all further advance, except by difficult and precipitous passes, already occupied by the Persians. Xenophon, having dislodged the enemy from the first ridge, returned to the main body of the army, which had remained in the plain. This must have been near Fynyk, where the very foot of the Kurdish mountains is first washed by the river. The spot agrees accurately with Xenophon's description, as it does with the distance. "The Greeks," says he, "came to a place where the river Tigris is, both from its depth and breadth, absolutely impassable; no road appeared, the craggy mountains of the Carduchians hanging over the river." Xenophon preferred the route across the mountains of Kurdistan, as it led into Armenia, a country from which they might choose their own road to the sea, and which abounded in villages and the necessaries of life. Beyond the Carduchian mountains there were, according to the prisoners, two roads into Armenia, one crossing the head waters of the principal branch of the Tigris, the other going round them; that is, leaving them to the left. These are the roads to this day followed by caravans, one crossing the plains of Kherzan to Diarbekir, and thence, by well-known mountain-passes to Kharput, the other passing through Bitlis. Xenophon chose the latter. The villages in the valleys and recesses of the mountains are still found around Funduk; and, on their first day's march over the Carduchian hills, the Greeks probably reached the neighbourhood of this village. There now remained about ten parasangs to the plain through which flows the eastern branch of the Tigris; but the country was difficult, and at this time of the year (nearly midwinter)[15], the lower road along the river was impassable. The Greeks had, therefore, to force their way over a series of difficult passes, all stoutly defended by warlike tribes. They were consequently four days in reaching the Centritis, or eastern Tigris, the united waters of the rivers of Bitlis, Sert, and Bohtan. It was impossible to cross the river at this spot in the face of the enemy. At length, a ford was discovered higher up, and Xenophon, by skilful strategy, effected the passage. This must have been at a short distance from Tilleh, as the river, narrowed between rocky banks, is no longer fordable higher up.