Strabo Geography 3.4.12

[12] Immediately after passing Idubeda, you enter on Keltiberia, a large and irregular country. It is for the most part rugged, and watered by rivers, being traversed by the Guadiana, ¹ the Tagus, and many other of the rivers which flow into the western sea, but have their sources in Keltiberia. Of their number is the Douro, which flows by Numantia ² and Serguntia. The Guadalquiver ³ rises in Orospeda, and after passing through Oretania, enters Baetica. The Berones inhabit the districts north of the Keltiberians, and are neighbours of the Conish Cantabrians. They likewise had their origin in the Keltic expedition. Their city is Varia, ⁴ situated near to the passage of the Ebro. They are adjacent to the Bardyitae, now called the Bardyli. ⁵ To the west [of the Keltiberians] are certain of the Astures, Gallicians, and Vaccaei, besides Vettones and Carpetani. On the south are the Oretani, and the other inhabitants of Orospeda, both Bastetani and Edetani, ⁶ and to the east is Idubeda.