An impressive iron cross stands out on the top of it and is not the only link that this fortress has with Christianity: in fact, its name evokes the memory of a medieval church that has now disappeared. The nuraghe San Pietro stands on the edge of the town of Ussaramanna, on the top of a hill surrounded by the rolling landscape between sa Jara Manna (the Giara di Gesturi) and the Giara di Siddi. It is a complex building, constructed with large sandstone blocks, in which there is a keep, standing ten metres high and with a diameter of 13 metres, surrounded by a bastion with four towers connected by a curtain wall. Three of the four lateral towers have diameters of around nine metres, while the one in the north-eastern corner is larger: its diameter is the same as that of the keep. This distinctive feature has been explained by the theory that this may originally have been a trefoil nuraghe and was subsequently modified by inserting the fourth tower.

From the entrance, located on the south-east side, a corridor opens up and has an ogival roof, which has partially collapsed. Before entering the main chamber of the keep, on the left you will notice the remains of the flight of steps that provided access to the upper level. In the internal space, which has a circular layout and is now without a roof, you can see two opposing niches, also with an ogival ceiling. Another room appears in front of the stairwell and is difficult to interpret: judging from its position and shape, it appears to be a sentry box. Around the building, you can also see traces of rooms with a quadrangular layout: it is thought that they date back to Roman times, providing evidence of a thousand years of continuity of use of the site. The possibility that the nuraghe also had funerary functions until the Byzantine era cannot be excluded.

In the territory of Ussaramanna, known for the very high quality of its of olive oil and Malvasia and Nuragus wine production, there are traces of evidence of it being frequented since prehistoric times. The legacies dating back to the Bronze Age are not limited to San Pietro: in the village’s surroundings, you can also see the nuraghi Santa Barbara, Cabonu, Molas and su Sensu. Then, in the Bingias Beccias area, a necropolis dating back to the Imperial age has been discovered. You can continue your archaeological tour in the heart of Marmilla by moving a few kilometres east: in the territory of Siddi, you will find the majestic and well-preserved Giants’ Tomb of sa Dom’e s’Orku, made up of rows of large basalt blocks, as well as the park of sa Fogaia, with a nuraghe in a scenic position and a ‘garden’ of great natural value at its feet.