First news related to Nuraghe Mannu came from from A.Taramelli who in 1927 first explored this site. The area, rich in a large quantity of perfectly worked, square, basalt stones is characterized by the "nuraghe" which, despite the name, ("mannu" means large in Sardinian language) is a mono-tower building of modest dimensions, built with big basalt rocks laid in irregular rows. It is positioned beside the Codula of Fuili canyon, and could have been used as an extremely important sighting point, looking out to and communicating with other towers over the whole Gulf of Orosei. The east facing entrance is surmounted by an irregular lintel above which two rows of blocks are preserved. Above this lies a little window-hole for unloading. A corridor covered by flat rocks leads to the room, of elliptical form, that preserves two big raised niches. In the passage there is a staircase with a winding course that leaded to the terrace .

Around the "nuraghe" there is a vast village occupying several hectares. This is mostly covered by collapsed walls, by scrub and by thick bushes of "lentisco", its roots deeply buried amongst the buildings’ foundations.

In 1933, by giving an account of his sightings in the Dorgalese territory, A.Taramelli highlighted the presence of blocks of stone amongst the structures built during ancient Roman times. According to this scholar, these Roman dwellings were constructed with architectural elements of ancient "Protosardi" buildings which had been used for religious ceremonies, and had risen in the proximities of the inhabited area. The finding of some blocks of basalt with geometric shapes engraved on the main side of the blocks, gave further proof to the archaeologist on the presence of original places of cult, which could somehow be compared with the decorative and building techniques that he had found in other places in Sardinia which he had previously excavated: see Sardara, Serri, Bonorva and Nuragus.

The rectangular and square buildings explored by Taramelli were at first thought to be for military use, from which soldiers were able to check the coast-line and possible landings of enemies, whom might leave provisions and weapons to the natives, and could feed the guerrilla in the areas inland, as the latter opposed the politics of conquest of the Romans. To reach a clearer understanding the area was excavated, finding ceramic and stone materials and tools, which proved the area was inhabited at different times.

Since 1994, Nuraghe Mannu has been the object of eight excavations driven by the Archaeological Superintendence and undertaken by around 700 volunteers. The surveys and diggings of the village and of the "nuraghe" have discovered findings which date the first building phase of the village in the evolved phase of the Middle Bronze Age (1500 b.c.). The most frequented phase, on the base of the quantity of the recovered materials, had certainly been that of the Recent and Final Bronze Age (1200-1000 b.c.). Among the ceramic materials that enable us to diagnose a precise cultural period, other objects and tools of daily use were recovered, such as stoves, river pebbles used as pestles and burnishers; different millstones that attest an intense cultivation of corn, grain, cereals, etc. In the proximity of the excavations where "Nuragic" material was found, a Roman building has been explored; this had been built above the remains of the preexisting "nuragic" dwellings; in fact there is here a dressed stone of trapezoidal form with three holes on the shortest side. This type of stone "to notches" (“dentelli”) is typical of the most recent typology of the so called "giants' tombs" the use of which was named after the type of grave with the "stele centinata" - high upright stone slab with round top - situated at the center of the semicircular “esedra” - ceremonial area delimited by upright stone slabs or walls in front of the tomb -, that delimited the external cult area. In the building were found fragments of roof tiles belonging to the original roof, fragments of cafeteria vases and kitchen tools dating from the IV century a.c., fragments of glass, amber, bronze nails. Among the ceramic materials large pieces of “pithoi” - amphoras - were found which were used as containers for food, wine, oil, etc.

The excavations clearly show the remains of a real city, whose history must be further explored, both by extending the exploration to other buildings already delimited around the "nuraghe", and by investigating the most ancient underlying nuragic layers in order to understand any possible phases of abandonment and re-use and above all to understand the causes that lead to this.