## 4 Discussion
### The Purpose behind the Serravuda Hilltop Structure  
After proposing the anthropogenic origin of the vitrified structure of Serravuda and confirming the thermoluminescence data, the discussion shifts from its age, plausibly dating to the Late Bronze and Early Iron Age, to its destination and events that contributed to its vitrification. These two aspects may be connected. As early as 1972, [PERSON] speculated that the Serravuda vitrified rocks in the area could be the remains of pottery smelting furnaces or closed furnaces for the production of metals or alloys [11]. Consequently, the vitrification of the materials could be linked to human use of the structure. The possibility that ceramic activities took place on the summit of Serravuda in ancient times was initially considered due to the discovery, previously cited, of ceramic remains dating back to the 4 th-2 nd centuries BCE [11]. Nevertheless, several considerations, such as the location of the structures on the summit of a relief and their shape and size, as well as the absence of argillaceous material in the area, make this hypothesis completely implausible.  
Moreover, the size and geometry of the construction erected on the summit of Serravuda and our on-site observation on geochemical data relating to \"technophilic\" metals such as Cu, Zn, Ni, Co, Ag suggest a metallurgical furnace was built on the site highly improbable  
Excluding therefore the possibility that the vitrification of the Serravuda structure is linked to specific human activities involving fire, one can only assume this structure was erected exclusively for defensive purposes.  
There are a series of evidence to support this thesis. Firstly, the structure is built on the edges of an artificially flattened summit of the highest regional relief. Furthermore, its narrow, elongated shape is reminiscent of a defensive wall. Some evidence suggests that it originally extended along the entire perimeter of the hill [13]. Therefore, both its substantial dimensions and the construction techniques used align with the defensive structures known as \"wall circuits\", widespread in southern Italy [31]. These structures were built as early as the Early Bronze Age and saw significant expansion during the Iron Age, often associated with specific episodes of colonization of the region. Of particular interest in this context are the settlements of populations in areas very close to Serravuda, as documented in the of Colle Dogna site in Acri [32; 33]. In addition, the presence in Calabria of successive populations, namely the Oenotrians, Brutii, and then Romans, who settled in the region more or less permanently, in the time interval between the Middle Bronze and Early Iron Ages, is widely documented in the literature [34; 35; 36; 37].  
Based on these considerations, it can be affirmed that the fortified construction of Serravuda fits in well with the knowledge of the presence of human settlements in Calabria and Southern Italy in general. The fact remains that it is distinguished from all others solely by the fact that it underwent vitrification. This fact prompts a comparative discussion regarding vitrification processes that occurred in Serravuda and other ancient fortifications, particularly Iron Age vitrified forts in Northern Europe.