Polybius related: "... on his return thence (from the north), he traversed the whole of the coast of Europe from Gades to the Tanais." Some authors consider this leg a second voyage, as it does not seem likely he would pass by Marseille without refitting and refreshing the crew. It is striking that he encountered the border of Scythia, turned around, and went around Europe counter-clockwise until he came to the southern side of Scythia on the Black Sea. It is possible to speculate that he may have hoped to circumnavigate Europe, but the sources do not say. In other, even more speculative interpretations, Pytheas returned north and the Tanais is not the Don but is a northern river, such as the Elbe river.