Mazarrón port in the Late Roman period was a locality dedicated mainly to fishing and the production of saltings, with its other parallel industries (esparto grass, pottery), making up the grand coastal economic centres of the current Murician coastline. Along with markedly Roman traditions we see the appearance of Christian rituals, the presence of Jewish testimonials, or the invasion of peoples of possible Germanic option. There were two separated populated areas: one in the area of the actual port and the La Era and El Faro headlands; and one in Cabezo de la Molineta. Both had their respective cemetery. Alongside the economic strength of the coast, the interior of the existing municipality had in this period a marked rural character, with subsistence farming and very little left of the mining and metalworking activity.
Cartagena and Águilas, along with Mazarrón port, seemed to make up during Late antiquity the three grand coastal economic centres of the current Murcian coast, very linked to fishing activities.
In respect to the Mazarrón port inland hinterland, mining activity seems to have lasted only in
Coto Fortuna, there being recorded the existence on the top of the hill fortifications from the Late epoch. The mosque cemetary, on the Sierra del Algarrobo, indicates the presence of a rural population, probably with a subsistence economy, for which there is initially proposed a chronology of the 5th century.
Testimonies of the Mazarrón Port Late antiquity epoch are located especially around two different areas: the area of the old and current port, with the La Era hillock and the foothills of the lighthouse hillock; and the area of the La Molineta hillock and its foothills.
The salting factory was located next to the port installations, occupying an extensive site on the right side of the bay. There were modest office structures, warehouses or small industries related to the port and factory activities, which have been excavated at different sites. Behind the old port, in the area known as La Era, in 1990/1991 a series of family homes following classic models and a Late cemetery were excavated.
The other area occupied during the late Roman period is around the La Molineta hillock, which dominates the Mazarrón Port beach in parallel to the same. On the highest part of the hillock the La Molineta Late cemetery was found.
In the block of the old Serrano cinema, between Macetas, Cartagena and Trafalgar streets, there was a large water deposit with capacity for 13.5 million litres of water. It is dated as older, but in that epoch, already unused, it was used as a huge rubbish dump.
The excavations on the La Molineta hillock, next to parallel testimonies from the period of maximum salting activity, have allowed for the collection of singularly interesting information about the continuation of the occupation in the area up to the 6th century. Together with a strong survival of pagan beliefs, the cemetery confirms the penetration of Christianity among the population in the 4th century. Other iconic elements, such as the presence of seven-armed candlesticks, could also be Christian testimonies and not of the existence of a Jewish community in the town. The moment of crisis which reflects the port activity in the first half of the 5th century, is reflected in the La Molineta cemetery in the intentional destruction of a good part of the graves. From the historical point of view, a connection has been made between the incursions in the area by groups related to the vandals or other eastern German bands.
In order to pinpoint the final moment of the cemetery we have the discovery of coins hidden in one of the graves, among them some minted by vandals in North Africa. It is tempting to connect the end of activities in Mazarrón port and the hiding of the coins with the process of Byzantine power’s settlement in the south-east, with Cartagena as its capital, which was not unconnected with expeditions against vandal settlements in North Africa and the south-east of the peninsular. The Byzantine army disembarked in Cartagena untill 555, controlling the region up to 615, a date when Sisebuto reconquered the city for the visigoths.