Ussana lies on a flat stretch, undulated by low-rising fertile hills, including the Monte Zara and Monte Agutzu. Ussana is an important agricultural-pastoral hub with 4,200 inhabitants on the southern part of the Campidano plain, bordering Parteolla. The village preserves Campidanese houses, built in ladiri (mud and straw bricks), with the characteristic lolla, a porticoed loggia around the inner courtyard, and large entryways. Within the town is the parish church of San Sebastiano Martire, in Baroque style, built atop a 15th-century building. On a hill on the outskirts of the town stands the church of San Saturnino, whose original layout, repeatedly altered, dates back to the early 12th century. It has two naves divided by arches of limestone ashlars that rest on three columns, the shafts of which are Roman, as well as two Corinthian capitals (from the first half of the 1st century AD). In addition, it houses within the most important Roman artefact discovered in Ussana, a marble sarcophagus from the 3rd century AD, with rich sculptural adornments on the front and sides, originally destined to house the remains of a young patrician.