Samatzai lies on the slopes of Mount Titas, on the eastern fringes of Medio Campidano; it has always been an agricultural center, since the end of the 20th century also an industrial center since the establishment of one of the largest lime and cement factories in Italy, exploiting the lime quarries, a major resource of the area. Of the Trexentine style is the traditional urban planning and structure and architecture of the town: large, two-story, unfired earthen houses of a ‘peasant’ matrix surrounded by extensive courtyards. They face each other in streets around the 15th-century parish church of St. John the Baptist, which houses ancient wooden statues of saints and a splendid 16th-century solid silver astylar cross. The single-nave church is Gothic-Aragonese in layout, with a wooden roof supported by ogival arches and side chapels. Also of value is the 17th-century church of St. Barbara with a small portal surmounted by a window and a bell gable. In the countryside there is a shrine in honor of St. Peter, celebrated in mid-July. Also prominent in the historic center is the 18th-century grain mound, an interesting example of rural architecture, formerly a grain store, now a library and meeting hall. Also not to be missed is the ‘blacksmith’s house’ museum.
Samatzai was known in Antiquity as Santu Maccari, a village where the church of St. Mark was built, some ruins of which are preserved. Among the hypotheses about the present toponym is that of derivation from Samas, Mesopotamian sun god, which would reflect the nature of its sunny soil, unprotected by shrubby Mediterranean scrub. By ancient tradition, the largely cultivated land is divided into two parts: sartu de sus to the north and sartu de bàsciu to the southeast. It was inhabited since the Neolithic, as evidenced by the domus de Janas of the necropolis in the locality sa Rocca Pertunta. Of the later Bronze Age, the nuraghe su Nuraxi, in the locality of Domu is Abis, stands out.