Carales was the only city with Roman civic rights in Sardinia in Pliny's time (when it received the privilege is unknown) and by far the most important place in the island; a Roman colony had been founded at Turris Libisonis (Porto Torres) and others, later on, at Usellis and Cornus.
The towns were connected by a considerable network of roads, with a total length of 958 Roman miles according to the Itineraries, the most important of R which ran from Carales to Turris Libisonis (Porto Torres) through the centre of the island, passing Othoca (Oristano) and Forum Traiani.
Several milestones belonging to it have been discovered, including one of the time of Augustus and one of Claudius near Forum Traiani, and one of Nero near Turris Libisonis, though it was probably not completed right through until a later period (T.
Turris Libisonis was also connected with Othoca by a road along the west coast, passing through Tharros, Cornus and Bosa; this road went on to Tibula 2 (Capo della Testa) at the north extremity of the island and so by the coast to Olbia.
Oristano occupies the site of the Roman Othoca, the point at which the inland road and the coast road from Carales to Turris Libisonis bifurcated, but otherwise an unimportant place, overshadowed by Tharros.