It climbs to an elevation of 500 metres along the slopes of Mount San Lorenzo, a peak in the heart of Anglona, a region of which it was the capital in the Medieval period, in an area with an extraordinary concentration of prehistoric sites. Nulvi is a mountain agro-pastoral town of ancient roots, inhabited by almost three thousand residents and set 20 kilometres from Castelsardo and 25 from Sassari. Its income comes mainly from the production of cheese and excellent wines. It is the city of nuraghes: the municipality with the largest density of nuraghes with respect to its size: about 80 have been identified. The most noted of these are the four-lobed Alvu nuraghe, built of white, squared-off blocks and surrounded by numerous shed foundations; nuraghe Orria, along with the Giant’s Tomb on the mountain of the same name; and the Irru complex, which includes a nuraghe and an interesting limestone well temple (10-7th century BC). Sixteen metres long and seven metres wide, its tholos, vestibule and two atriums are still distinguishable. The well chamber is circular and four and a half metres deep.