The Nuraghe San Marco stands on the eastern outskirts of Genuri, on the slopes of the southwestern side of the Jara Manna, the largest and most famous Giara. The basalt used to build the monument came from the plateau, which was also a source of food and resources for the peoples who inhabited the Marmilla region, while marl was used for the restoration work that took place in later phases. The building has a complex structure, consisting of a keep and three towers, and it is surrounded by a rampart with five other towers, except for the north side, perhaps because the builders considered the natural protection of the Giara plateau sufficient.
Curiously, the southeast tower has a smaller diameter than the other two, while the northeast wall, which follows the profile of the central tower, has sometimes been interpreted as the wall of a fourth corner tower. In the space between the keep and the connecting curtain walls between the towers is a crescent-shaped courtyard, accessed through the entrance to the building on the south side. From the courtyard, which also contains a well, one enters the keep and the corridors leading to the side towers. Inside the keep, the space is cruciform, with two niches at the front and a third opposite the staircase. The northwest tower features six loopholes, two niches, and the absence of an entrance corridor. It opens directly onto the courtyard.
Archaeological research has revealed that between the Late Bronze Age and the Late Bronze Age, a destructive event occurred, with relative collapse and subsequent rebuilding: San Marco probably witnessed a – still mysterious – period of crisis and conflict between the Nuragic tribes between the 2nd and 1st millennium BC. The site shows traces of human presence in the Punic period, and there was undoubtedly a settlement there between the late Roman period and the Early Middle Ages. At least eleven "new" rooms were built or added over the nuraghe, some of which probably served as food storage rooms, while the courtyard and towers were used for various purposes, sometimes even for burials. sardegnaturismo.it/en/explore/nuraghe-san-marco