The Sette Sale complex on the Oppian Hill. Water infrastructure and the persistence of urban form

Between 1893 and 1901, a few decades after Rome became the capital of Italy, Rodolfo Lanciani drew up the Forma Urbis Romae, reconstructing the layout of the ancient city within the Aurelian Walls on the basis of the new knowledge that had emerged from the excavation works carried out during the city’s transformation. On this map, on the Oppian Hill, the Cistern of Sette Sale appears for the first time flanked on its eastern side by a basalt-paved road, the remains of which were uncovered during the earthworks for the construction of via Leopardi. Further east stand the Servian Walls, which, along their northward course, intersect the so-called Auditorium of Maecenas, also brought to light only shortly before through Lanciani’s excavations. South of the cistern appear the imposing structures of the Baths of Trajan and the Domus Aurea, one superimposed upon the other. When observing this dense concentration of archaeological features, it becomes evident that the earliest hypotheses concerning the attribution of the cistern — based primarily on its position — were flawed, leading to its association with Nero’s Domus rather than with the Baths. Only the archaeological excavations conducted between 1967 and 1981, through the discovery of the water-supply conduit serving the Baths and brick stamps dating to the Trajanic period, clarified the relationship between the cistern and the Trajanic complex. Thus, at first glance, the cistern’s orientation appears almost accidental. Yet a closer analysis suggests a coherent alignment between the Servian Walls, the basalt-paved road, the cistern, and the agger, perhaps the most decisive element. This massive defensive embankment profoundly reshaped the hill’s topography, creating an artificial rise that continued to influence the organisation of the urban landscape long after its construction.