From 1928 to 1946, it was a hamlet of the nearby town of Simaxis and shared its name. It was not until 1991 that Ollastra Simaxis became the present day Ollastra. It is a small farming town of 1200 inhabitants on the border between the Campidano plain of Oristano, from which it is 16 kilometres away, and the hills of the inland. During the Roman era it was crossed by Via Maxima. The town name derives from ollastu, i.e. wild olive, a tree that covers this particularly fertile land crossed by Tirso, the largest river of the island. Vineyards, citrus fruit orchards and fields of artichokes and other vegetables cover the flatlands near the town thanks in part to the Santa Vittoria dam. Some lands are set aside for the cultivation of cereals. To the north-west, the wild olives have been replaced by domestic olive trees, from the fruit of which excellent olive oils are obtained. To the south-west, rice is being cultivated in the reclaimed ancient swamp of Arcais. Consequently, the town’s economy relies heavily on farming, although a small contribution is also made by shepherding and artisanal production of carpets and baskets. The vernaccia, an almond and cheese sweet is a local specialty of note.