The Antiquarium Arborense Museum is located in Oristano . The reason why an archaeological museum was established in Oristano in 1938 lies in the moral legacy of Tharros, boasted by Oristano, which became the seat of the Archbishop and judge of Arborea in 1070, welcoming the refugees from Tharros.

Since then the people of Oristano transported the spolia, i.e. the marbles, columns, capitals and squared blocks of Tharros , from their mother city to build the cathedral, churches, monasteries, palaces and the turreted city walls.

The most conspicuous collections of Tharrense antiquities had been formed in Oristano, including those of the judge Francesco Spano, of the nobles Paolo Spano, Salvatore Carta and that of the antiquarian Giovannico Busachi. A part was purchased by the Cagliari museum, while another part remained in Oristano, where a young lawyer from Sèneghe (OR), Efisio Pischedda (1850-1930), began the creation of the largest private collection of antiquities existing in Sardinia.

The Pischedda collection became a point of reference for national and international archaeology: we can remember the visit of the French prehistorian Émile Cartailhac, of Friedrich Von Duhn, director of the Institut für Klassische Archäologie of the University of Heidelberg, Thomas Ashby director of the British Scholl in Rome , Giovanni Pinza, Giovanni Patroni, Antonio Taramelli and other scholars of great fame.

After the death of Pischedda, in 1930, the Superintendent of works of antiquity and art of Sardinia, Doro Levi, obtained from the Municipality of Oristano the commitment for the purchase of the important collection, which constituted the municipal fund of the Antiquarium Arborense since 1938. The current neoclassical headquarters from the mid-nineteenth century, which belonged to senator Salvatore Parpaglia, was opened to the public on 28 November 1992.