Sardinia's landscape is rich in bronze age remains that can be seen everywhere you go. Most conspicuous are the gravechambers cut out in rocky hillsides, the Domus de Janas, or the megalithic gravestructures called Tombe di Giganti and dolmens, but most of all stand out the numerous bronze age towers of natural stone, the nuraghi. As Giovanni Lilliu put it: ...i nuraghi significano fascino di Sardegna, oltre la natura vergine e sconfinata, oltre il mare.. He was the most important archaeologist for the Sardinian prehistory and bronze age cultures 1. The fascination of the towers is not only the massive structure that survived thousands of years, but also the large number, more than 6500 are still present on the island. These range from simple towers to complex multitower structures that remind us of medieval castles with their walls, bastions and towers, with the difference that nuraghi have sineously curved and rounded forms.
When and who built these nuraghi, what use they had and how they related to each other and their environment has been subject to much research and discussion. It has also leaded to the conception of many theories more or less fantastic about the towers and the people that built them, which is not so strange considering the large number of still existing nuraghi. But it is specifically scientific research that will have to give answers to these questions. In this article you will find an extract of what is known about the nuraghi, how they were built, conceived and their architecture, where they are located and what function they might have had. There is also a paragraph on historical and archaeological research of the past centuries and what future is reserved for the numerous towers.
Where does the word nuraghe come from?
The word nuraghe derives from the pre-indoeuropean or sub-mediterranean root: nur. It means hollow construction or hollow heap of stones and in Sardinian dialect the word nurra is still used to indicate a cave, heap or pile of stones 2. The word nur and it's derived forms are still present in many geographical indications: nuraghe, nurake, nuraxi, nuracci, nuracu, nuragi, like in Nuraminis, Nuraxinieddu, Nurachi, Nurri and the region of Nurra near Alghero. The plural is nuraghi but also nuraghes is used.
Archaeological dating of the Nuraghi
When were the nuraghi built? In archaeology conclusions are almost always based on circumstantial evidence to determine when a nuraghe was used at it's earliest. Evidence comes from excavations in and around the nuraghi and consists mainly of the refuse that people have left behind or from hearths or cooking fires. If these remains are organical the C14 dating method can be applied, if the remains are anorganic, like sherds of ceramic pots, then classification based on tipology is used. In the last case the find is related to known artefacts from other excavations where a more certain date has been attributed and so the age of an artefact is derived from it. In both ways there is always a margin of error to take in account.
For accurate dating it is important to determine the layer from which the artefact (object) has come from. If this layer lies below for instance a layer with a find of a roman coin one can assume that artefacts (earring, bone needle, obsidian cutting tool) from this lower layer are older. Ofcourse layers can be disturbed by later ploughing or digging of holes, but that usually shows.
Development in architecture can be used as a dating method for nuraghi. The more the stones have been worked over to get a rectangular form, the later the date of the nuraghe will be, but also the more complex the nuraghe is the later it has been built and amplified. Another example is which architectural features have been used, the relation between the thickness of the walls and the height of the inner room: improved techniques were used to create more room without making the walls thicker to bear the weight and still not endanger the stability of the structure 3. Through the obsidian tools that have been found in nuraghi dating using the method of obsidian hydratation has been used in many cases. The vulcanic glass is found abundantly on the slopes of the Monte Arci and it was still used frequently in the bronze age to make cutting tools 4.
Archaeologists have come with these methods to conclusions about the age of a nuraghe that was mostly based on the oldest artefacts found and which have been put in relation to similar contemporary studies and excavations. A consensus on the age and development of the nuraghi in the bronze age has been established which has been accepted widely by scientists even though some still may have different views on the subject 5.
Since the Calcolithic (copper age) in Sardinia already megalithic structures have been built which have been identified as the predecessors of the nuraghi, the proto- or pseudonuraghi . These structures are different in form but similar in building technique of piled stones with a corridor and a stairway leading to a platform. The platform could be up to six metres in height 6. In the late Calcolithic and early Bronze age this form of the proto-nuraghe evolved into that of the classical nuraghe with a round chamber and cupola shaped ceiling. This first phase in nuragic building has been dated back to the period of 1800 and 1500 BC. At first scientists ascribed the development of the nuraghe with cupola shaped room (tholos) to the contacts with the Mycenean and Minoan world where this feature was used in gravestructures. From research has emerged however that that should be corrected at least for the origin of megalithic building with cupola shaped vaults. There existed already mixed structures of proto-nuraghi and nuraghi (Monte Baranta, Bruncu Madugui) as a result of western European megalithic culutural influences and also analogous structures of towers have developed on Corsica (torreano) and the Balearic islands (talaiots). On Sardinia this development of the megalithic building lead to the final form of the round nuraghe and the chamber with the cupola shaped vault 7. An example of an early nuraghe is that of Duos Nuraghes near Birori dated to around 1800 BC 8. The central tower of Su Nuraxi near Barumini belongs to the oldest part of the complex nuraghe and has been dated with C14 to 1500 BC, at the end of the first nuragic period. The tower has been estimated to have been 20 metres high with three stories of rooms with tholos vaults 9.
In the Bronze age two dramatic events took place that had their repercussions on the east and the west Mediterranean, including Sardinia. The first event was the decline of the palace culture of the Minoan period on Crete and the rise of the Myceneans, between 1500 and 1400 BC. The second event was the time of the incursions of the Sea People in Egypt and the decline of the Mycenean palace culture, around 1200 BC 10. It was around 1200 BC that on Sardinia complex nuraghi were built, an amplification of a central nuraghe with one or more additional towers, a small courtyard and even additional defensive walls and minor towers. Lilliu has called this period La bella età dei nuraghi, the climax of the nuraghe-culture 11. It has been estimated that of the 6500 still existing towers around 2000 are of the complex type.
Since 900 BC, when contacts with the east intensified again through sirian-palestinese and phoenician merchants, the socio-political landscape changed and the importance of the nuraghe as stronghold declined while the importance of the nuraghe-villages became more apparant 12. New nuraghi were no longer built and those that were still in use were only repaired or maintained as has been found with for example nuraghe Genna Maria 13.
The architecture of the Nuraghe
Nuraghi are built out of natural stones, more or less cut to fit better or to create a smoother surface on the outside. The stones were placed without the use of any kind of cement. In the lower part larger stones are used and towards the top the stones decrease in size and weight. The tower has a truncated conical form, wider at the bottom and with a platform on top. Because the next row of stones is slightly shifted to fit between two stones a pattern of diagonal lines can be seen in the walls. The walls are very thick, up to a few metres and are thinner to the top. On one side, usually south or southeast, the only opening is a doorway with a large lintel. The lintel does not carry any weight of the walls in the middle, all weight is diverted to the sides of the trapezium formed opening. In fact often above the lintel there is a triangular opening like a small window where light and air could pass.
The doorway gives usually access to a short corridor that lead to the central circular room. This central room has a cupola shaped vault that was obtained by placing the stones in circles that are smaller towards the top. This vault, called tholos or also false cupola in architecture, maintained itself in position under it's own weight. In the summit a large stone, part of the floor of the upper room or of the uppermost platform, covered the last opening. Measurements of the thickness of the walls compared to the height of the vault of the main room gives an indexnumber that determines the age of the nuraghe: in the course of time building techniques permitted thinner walls and larger inner rooms 14.
In the central room of a nuraghe often niches have been created that have an elongated triangular form towards the top. The number of niches can differ per nuraghe. In large nuraghi the central room could be divided horizontally by a platform, creating an extra storey and some nuraghi have openings halfway up in the inner room that lead to corridors or secret rooms. The upper rooms and platform could be reached through a staircase that was incorporated in the thick outer wall of the nuraghe and winds up in a circle around the central room to the next floor. The entrance to this staircase is on the left when entering the nuraghe, departing from the small corridor that leads to the central room. On the opposite side often a niche is left, called the niche of the guard. In some nuraghi there are left openings in the outer wall to let air and light fall into the stairway, they have the shape of loop-holes.
a simple nuraghe tower
By using large stones anchored in the walls an overhanging platform was obtained on top of the tower. The large stones have been found near many nuraghi and this made a reconstruction of the actual towers possible, even though the upper parts including the platforms have been destroyed. The parapet could have been in wood and clay and in some cases in stone. Complex nuraghi are known to have a large extended platform that was created by the two storey high additional towers where the central tower was three storeys high (for example Nuraghe Losa) 15.
How were the nuraghi built?
There is little known about how the nuraghi were built. There are no written sources. What we know can only be deduced from the nuraghi themselves and what we know about building techniques from the Bronze age. The kind of stones used has been determined by the environment and what was available. The most durable stone has been basalt which is abundant in Sardinia. Also marl was used like in Nuraghe Genna Maria, but that would wear out and undermine the stable structure of the building. The largest stones were used for the foundations, the higher one got the smaller the stones were, and so easier to use. For the large stones and the lintel it has been proposed that in the Bronze age wooden cranes could have been used 16. On the outer side of some nuraghi holes have been found, about 30 centimetres wide, that could have been used to position large beams of wood for a kind of ramp that reached to the first floor of the tower and was used to carry the stones for the upper storeys 17. In his book on the nuraghi Webster calculates the manhours necessary to build a nuraghe with an average of 3000 blocks of stone. Including the retrieval of the blocks in the immediate environment, the transportation, the working over of the stones to fit them Webster arives at 3600 man-days of work. The available manpower would have been 40 man-days per family which makes the building of a nuraghe take twelve years 18.
Typology of the Nuraghi
One main distinction in the architecture of the nuraghi is that of the simple towers (monotorre) and the complex nuraghi with several additional towers (polilobati). The simple nuraghi can be distinguished by the number of niches in the central room, whether there is an internal staircase and the indexnumber of the thickness of the walls and the height of the tholos cupola of the central room. The oldest building method was that of roughly shaped stones, polygonal shape. After 1500 BC the building technique became more sophisticated shaping the stones in a more regular and rectangular fashion into t-shaped forms that would be anchored in the wall, obtaining a smoother surface 19. In time the central rooms became higher and the walls less thick, creating more elegant towerstructures.
The complex nuraghi are distinguished by the number of additional towers that have been added to the original central tower: bilobato (two towers) trilobato (three towers like Nuraghe Losa), quadrilobato (four towers like Su Nuraxi) up to even seven towers. Often these complex nuraghi were also enhanced with an outer wall with additional towers so that a complex could count up to seventeen towers (Nuraghe Arrubiu) 20. These additional towers can have loop-holes on one side.
Webster distinguishes throughout the period of 1300-900 BC three different classes of nuraghi: Class I nuraghe-villages with simple towers, Class II complex nuraghi with a nuraghe village and Class III complex nuraghi with additional walls, bastions and towers. A Class III example of complex nuraghi would be Nuraghe Losa, Su Nuraxi and Nuraghe Genna Maria 21.
Geografical distribution and geological location: the nurografic chart
(source: Lilliu 2003 p 563 - elaborated by T Kriek)
average number of nuraghi per km2
Manca in his book states that the nuraghi have never been counted one by one to establish how many there really are and they have never been mapped 22. The maps that have been drawn were based on statistical data or only maps of partial area's like the Nurra or the Marghine-Planargia region 23. The statistical data is derived from the density of nuraghi per square kilometre. From these data it appears that most nuraghi are located in the northwest (Nurra, Alghero, Sassari) and central west (Planargia-Marghine) and in the central regions of the Marmilla, the Trexenta and the Sarcidano.
Research on the relation of the location of a nuraghe and the nearest watersource revealed that 51,1% of the towers can be found at less than 250 metres of a source 24.
It appears from these studies that there are several regions where nuraghi are not so frequent: the north (Olbia, Santa Teresa di Gallura) and the south (the Iglesiente, the plains of the Campidano, the Sarrabus near Cagliari). This could be explained in several ways and helps to understand the geographical distribution. The Campidano, which is the most extended fertile plain of Sardinia, counts little nuraghi, but other fertile plains like the Nurra or the peninsula of Sinis have a very high density of nuraghi. This is because one of the main conditions to build a nuraghe is the presence of suitable building material. In the Campidano plain this material is more scarce while in other area's the rock is too hard to be used like granite 25. It is also possible that in the fertile plains of the Campidano that have been under a more efficient Punic and Roman control the nuraghi have been dismantled. Another reason again might be that certain clans did not build nuraghi or much less. And then ofcourse where the density of population was much lower, like in mountaneous area's as the Iglesiente, there may not have been sufficient reason or manpower available to build towers. (continued on the next page.)
1 Lilliu 2006, p 34
2 Lilliu 2003, p 562, Lilliu 2006, p 36
3 Michels 1987, p 167 ff, Lilliu 2006, p 39
4 see Renfrew and Bahn for the methods used in archaeology. Michels 1987, p 119-125
5 compare Michels 1987 regarding Nuraghe Toscono, p167, he dates the nuraghe to around 900 BC)
6 Lilliu 2003, p 203-214
7 Lilliu 2003, p 317-318; Melis 2003, p 8-10 , Melis maintains a different start and end time for the nuragic period with a hundred years difference; Webster 1996, p 92
8 Webster 1996, p 94
9 Lilliu 2003, p 370, 371
10 Biers 1996, p 23-96; Lilliu 2003, p 365,366, 411, 412
11 Lilliu 2003, p 413; Melis 2003, p 17
12 see Michels 1987, a study of nuragic settlment in the Marghine area with traces of use of around 900 BC.
13 Webster 1996, p 157-159
14 Lilliu 1982, p 34-35
15 The information comes mainly from Lilliu 2003, p 571-590 and Melis 2003, p 12-17 and own observation. Other sources use the same description.
16 Manca 2004, p 16,17
17 Lilliu 2003, p 591; Lilliu 2006, p 39
18 Webster 1996, p 95-96
19 Lilliu 2003, p 579,580
20 Lilliu 2003, p 582 e.v.. Lilliu 1987, p 62-85; Melis 2003, p 17-22
21 Webster 1996, p 110-125
22 Manca 2004, p 8
23 One such research is done by Alberto Moravetti in Moravetti 1992
24 Lilliu 2003, p 562 , see also Michels 1987 the location of the nuraghi in the Marghine area related to known water sources on p,9
25 Webster 1996, p 98