This is enough of the story told by Etearchus the Ammonian; except he said that the Nasamonians returned, as the men of Cyrene told me, and that the people to whose country they came were all wizards; as to the river that ran past the city, Etearchus guessed it to be the Nile ; and reason proves as much. For the Nile flows from Libya , right through the middle of it; and as I guess, reasoning about things unknown from visible signs, it rises proportionally as far away as does the Ister. For the Ister flows from the land of the Celts and the city of Pyrene through the very middle of Europe ; now the Celts live beyond the Pillars of Heracles, being neighbors of the Cynesii, who are the westernmost of all the peoples inhabiting Europe . The Ister, then, flows clean across Europe and ends its course in the Euxine sea , at Istria , which is inhabited by Milesian colonists.