Some of the rock chambers originally intended for tombs were afterwards converted, perhaps under pressure of necessity, into habitations, as in the case of the so-called " Prison of Socrates," which consists of three chambers horizontally excavated and a small round apartment of the " beehive " type.
The manner of their arrangement seems to indicate clearly that they were intended to be fortified habitations, not tombs or temples.
We thus have two classes of tombs in connexion with the nuraghi, and if these were to be held to be tombs also, habitations would be entirely wanting.'
They consist of chambers of various sizes, some of which were evidently human habitations, together with cisterns, channels, seats, steps, terraces and quadrangular tombs, all cut in the rock.
These habitations would naturally in the first instance lie in close proximity to the western approach; after the building of the Pelasgicum they seem to have extended beyond its walls towards the south and south-west - towards the sea and the waters of the Ilissus.
