Res Gestae

The tomb of the prince, who, as we said, built these roads, is at Susa next to the walls, and his shades are devoutly venerated for a double reason: because he had ruled his subjects with a just government, and when admitted to alliance with the Roman state, procured eternal peace for his nation.

And although this road which I have described is the middle one, the short cut, and the more frequented, yet there are also others, constructed long before at various times.