Strabo Geography 4.1.3

[3] The configuration of this country resembles a parallelogram, the western side of which is traced by the Pyrenees, the north by the Cevennes; as for the other two sides, the south is bounded by the sea between the Pyrenees and Marseilles, and the east partly by the Alps, ¹ and partly by a line drawn perpendicularly from these mountains to the foot of the Cevennes, which extend towards the Rhone, and form a right angle with the aforesaid perpendicular drawn from the Alps. To the southern side of this parallelogram we must add the sea-coast inhabited by the Massilienses ² and Salyes, ³ as far as the country of the Ligurians, the confines of Italy, and the river Var. This river, as we have said before, ⁴ is the boundary of the Narbonnaise and Italy. It is but small in summer, but in winter swells to a breadth of seven stadia. From thence the coast extends to the temple of the Pyrenaean Venus, ⁵ which is the boundary between this province and Iberia. Some, however, assert that the spot where the Trophies of Pompey stand is the boundary between Iberia and Keltica. From thence to Narbonne is 63 miles; from Narbonne to Nemausus, ⁶ 88; from Nemausus through Ugernum ⁷ and Tarusco, to the hot waters called Sextiae ⁸ near Marseilles, 53; ⁹ from thence to Antipolis and the river Var, 73; making in the total 277 miles. Some set down the distance from the temple of Venus to the Var at 2600 stadia; while others increase this number by 200 stadia; for there are different opinions as to these distances. As for the other road, which traverses the [countries of the] Vocontii ¹⁰ and Cottius, ¹¹ from Nemausus ¹² to Ugernum and Tarusco, the route is common; from thence [it branches off in two directions], one through Druentia and Caballio, ¹³ to the frontiers of the Vocontii and the commencement of the ascent of the Alps, which is 63 miles; the other is reckoned at 99 miles from the same point to the other extremity of the Vocontii, bordering on the state of Cottius, as far as the village of Ebrodunum. ¹⁴ The distance is said to be the same by the route through the village of Brigantium, ¹⁵ Scingomagus, ¹⁶ and the passage of the Alps to Ocelum, ¹⁷ which is the limit of the country of Cottius. However, it is considered to be Italy from Scingomagus. And Ocelum is 28 miles beyond this.