Following a period of scarce archaeological details, which began with the Byzantine conquest of the area, we find news of the area in the 12th and 13th centuries, when Islamic sources speak to us of the port of Susaña in this zone
From the time of the Byzantine settlement of power in the area there is a lack of archaeological information, which leads to a dark period. It will not be until the 12th and 13th centuries that we find news of the Mazarrón zone.
During the Islamic era, written sources (al-Idrisi) speak of Susaña as a good port, not far from the town, 24 miles from Cartagena and 12 from Águilas (Hins-Aquila). The old name of Almazarrón, according to the Royal Academy dictionary, comes from the Arab word al-mezer (ochre or red), although it is also usually related to the Arab word marza-arón (living or alert). Nevertheless, the existing town of Mazarrón does not seem to have been occupied until the Christian era, putting the Islamic population nucleus around the current castle or Cantarranas tower. Other concentrations of population were around important fortifications, such as the Carlantín (La Majada) or Pastrana castle.
Archaeologically, for Mazarrón Port we only have specific discoveries of medieval materials among the remnants from the underwater dredging, which are testimony to a certain commercial activity, as well as to the presence of scarce tombs of Islamic ritual in the excavations on Fábrica Street, in the area which dominates the old port and which is evidence of the existence of a population nucleus.