In the late 1980s, on the hill of Murru Mannu, to the west of the tophet and close to the fortifications, there was a very important discovery of an industrial workshop area for iron metallurgy. The area was characterized by a succession of dark burnt layers containing metallurgy waste (fragments of the walls of furnaces, slags resulted from melted metals, etc.), mixed with a large amounts of materials used to craft residential, funerary, and sacred items.

Laboratory tests carried out on these metallurgical materials have established that the iron came mainly from the Montiferru mine and proved an advanced knowledge of technological processes.
The workshop area was in use from the 5^th to the end of the 4^th century BC. In the following century, the workshop area was taken apart and the land was occupied to build the foundation of a monumental structure, perhaps one of the fortifications constructed with recycled blocks. Some of these probably came from Punic sacred buildings, as suggested by their shape and a Punic sacred inscriptions engraved on the blocks.