The settlement of the Punic-Roman city of Tharros was located on the eastern slope of the hill of San Giovanni and on the top of the hill of Su Murru Mannu, the latter of which has been partially explored.
As for the neighborhoods of San Giovanni, their long existence, the looting that has taken place there from medieval times, and the lack of published excavation data, prevents us from knowing very much about the structures built along the eastern side of the hill. The San Giovanni settlements are arranged on terraces dug into the sloping bank of the sandstone outcroppings and were probably of Punic origin. Although most of them dated back to the Roman period, the houses were constructed in the Punic style, mainly of squared blocks of sandstone with interstices filled with rubble.

The housing plans in Tharros vary but are generally of one of several distinct Punic styles: houses with a corridor that leads to an interior courtyard around which rooms were arranged; houses with a courtyard in front of the residential area; houses divided into two elongated rooms; and, houses with elongated openings and rooms laid out along the opening. The floors were either simply pounded into the ground or were made of earthenware (lime, aggregates and small fragments of pottery). Roofs were flat and made with natural materials, e.g., wooden beams, reeds, and tree branches. Fresh water was very important and the water supply was ensured by the use of elongated underground tanks known as bagnarola orbasins, where water was stored. Such tanks are typical of Punic construction and continued to be used in later periods when the Romans build aqueducts to transport water into the city.
The road network in Tharros was very irregular and built between the natural rock outcroppings. The roads were sometimes marked by furrows produced by the passage of wagons.
It is evident that many of these structures were built with techniques that were typically Punic, which is also confirmed by the numerous characteristically Punic cisterns present in the area. However, it is not easy to determine whether there were preexisting buildings used for centuries or, more likely, Roman buildings built with Punic techniques.
During the Roman Imperial period, the city experienced major urbanization projects which included the installation of an effective drainage system dug below the road surface where sewage flowed from both public and private buildings to be discharged into the sea. In the same period, the bumpy surfaced Punic roads were repaved with large black volcanic paving stones (basalt), which made them much more conducive to travel.

In the district of Murru Mannu, which was probably urbanized in Roman times, the streets were developed so that they intersected at right angles, thus allowing the use of blocks of uniform shape. The major road in this area, named Cardo Maximus, was probably used primarily as a ceremonial passage way because there are no traces of railway furrows. Many private buildings opened onto this road, some of which were probably used as workshops.