The archaeological area is located in Gremanu or Madau, near the Caravai Pass (1118 m above sea level), on the NE side of Gennargentu.
The complex, one of the most significant in Nuragic Sardinia, covers more than seven hectares on a slope.
It consists upstream of a series of springs and wells for the collection and collection of water, downstream of a village with a sacred area. Not far away there is a necropolis of tombs of giants.
The fountains and wells are inserted inside a semicircular wall.
From a first source, built in isodome work, the water was channeled, through a small channel, to the temple and housing complex located further downstream.
On the d. side of the wall there is a rectangular basin made of T-shaped basalt blocks connected by lead and wooden clamps with a bottom covered with trachyte and tuff plates; it was probably used for ritual ablutions.
A well is located inside a circular environment adjacent to the tank. The building has a 'tholos' roof. Inside, bronze pins and daggers, necklace elements and filthy containers for drawing water have been found. The materials date back to the recent-final Bronze (XII-IX century BC)
Downstream, inside a large rectangular “temenos” (length about 70.00 m), are the religious buildings: a single-tower nuraghe used for ritual purposes in the moments following its construction is particularly interesting.
The building has an arched entrance that leads into a circular chamber (diam. m 9.00) with a floor paved with blocks of schist and granite. The room has a niche on the NO side, and a seat on the SO side. On the opposite side of the entrance, there is a wall made of nine granite orthostats to form a sort of plinth: the traces of fire and waste found on the floor in front lead to the hypothesis that this area of the room was connected to the fusion activity. The sector in front is delimited by a wall that developed at the center of the environment. The wall is made of alternating rows of trachyte and basalt, with blocks decorated with zig-zag engravings and raised protomes; on the top were engraved with bronze votive swords.
The wall structures and the diameter of the environment have led to the hypothesis of a “tholos” type of roof, with a central hole as a vent for the fusion fires. It cannot be ruled out that lead was fused in the building, which is widely present in veins in the surrounding area.
The second building is a “Megaron” temple, with a rectangular plan (length 11.50 m) and a straight façade, which is accessed through a rectangular entrance that leads into the vestibule (length m 2.00; width m 2.60). A short corridor leads into the second rectangular compartment (length 4.80 m; width 2.00 m).
The structure dates back to the recent Bronze Age (13th century BC).
Both inside and outside the temples, numerous stone bases with holes have been found, where, by pouring molten bronze, figurative bronzes and votive swords were fixed.
The third temple has a rectangular plan (length 10.00 m) and an apsided back wall. A quadrangular vestibule leads into the cell with a paved floor.
The entire Gremanu complex is believed to have overlapped a Middle Bronze settlement (15th century BC).

History of excavations
The area was the subject of a series of excavation campaigns from 1989 to the end of the nineties, by the Superintendence for Archaeological Heritage of Sassari and Nuoro, under the direction of Maria Ausilia Fadda.

Bibliography
M.A. Fadda, “Fonni (Nuoro). Località Gremanu, Complesso di Fonti”, in Bulletin of Archaeology, 13-15, 1992, pp. 169-170;
M.A. Fadda, “Fonni (Nuoro). Madau or Gremanu Nuragic Complex”, in Bulletin of Archaeology, 19-21, 1993, pp. 176-181; M.A. Fadda, “Fonni (Nuoro). Location: Germanu. Complex of Nuragic Temples”, in Bulletin of Archaeology, 43-45, 1997, pp. 242-245;
M.A. Fadda, “The Nuragic Architects of Gremanu”, in Living Archaeology, n. 62, May-June 1997, pp. 70-75.

How to get there
Leave the town of Nuoro, take the SS 389 in the direction of Mamoiada; after passing the town, continue to Fonni, turning off to Pratobello. Continue on the old road to Lanusei and, after about 9 km, turn right into a dirt road closed by a gate: the archaeological area is just a few hundred meters away.