Preventive archaeological excavations at Parco delle Acacie, in the Pietralata district on Rome’s eastern outskirts, have revealed a remarkably rich archaeological landscape documenting nearly uninterrupted occupation from the 5th century BC to the 3rd century AD. The discoveries significantly revise long-held views of this area as marginal to the ancient city.

Investigations across roughly one hectare have brought to light a dense sequence of features organized around an ancient road axis crossing terrain shaped by a watercourse flowing toward the Aniene River. The road evolved over time—from compacted earth to rock-cut stretches—and was formalized during the Middle Republican period (3rd century BC) with substantial retaining works. Continued upgrades in the early Imperial period attest to prolonged use before gradual abandonment in the 2nd–3rd centuries AD.

Among the most notable finds is a small Republican-era shrine (sacellum) with a rectangular plan, built over a decommissioned votive deposit. Architectural remains and associated offerings suggest a cultic function linked to Hercules, a deity widely venerated along nearby routes such as the Via Tiburtina. Coins indicate construction between the late 3rd and 2nd centuries BC.

Close by, excavators identified an aristocratic funerary complex comprising two chamber tombs accessed by parallel corridors. Dating to the 4th–3rd centuries BC, the tombs yielded stone sarcophagi and urns, fine ceramics, personal items, and evidence of medical intervention on one individual. The scale and quality of the architecture point to a wealthy and influential family group controlling this territory in the Republican period.

Dominating the site are two monumental cistern-like structures from the 2nd century BC. The larger eastern basin (about 28 × 10 m) was built in opus incertum, supplied by channels from nearby slopes and the watercourse. Its precise function remains under study, with finds hinting at either cultic or productive uses. A second, deeper basin to the south (21 × 9.2 m), cut into tuff and accessed by ramps, lacks clear water inlets or outlets. Its form finds parallels with a similar structure at Gabii, where a sacred role has been proposed. Both structures were abandoned by the 2nd century AD.

Together, the discoveries demonstrate the long-term vitality and complexity of Rome’s eastern periphery, underscoring how preventive archaeology can integrate urban development with heritage protection. Further study is planned with the aim of enhancing the area and sharing these findings with the public.