On the Acropolis of Populonia, traces have resurfaced of a place once dedicated to well-being and social life: a Roman bath complex built over two thousand years ago.
Today, the ArcheoPopulonia project tells a new chapter in the city’s history, giving voice once again to one of its most vibrant and fascinating spaces.
New investigations
on the Acropolis
The ArcheoPopulonia Project
In August–September 2024 and May–June 2025, the first two excavation campaigns are carried out on the Acropolis of Populonia, promoted by the Chair of Classical Archaeology at the University of Pisa.
The investigations are conducted as part of the activities outlined in the agreement between the Department of Civilization and Forms of Knowledge, Parchi Val di Cornia S.p.A., and the Superintendency of Archaeology, Fine Arts and Landscape for the provinces of Pisa and Livorno.
The aim of this collaboration is to strengthen a network of research and enhancement that connects universities and local institutions, with the goal of deepening the knowledge and public appreciation of the heritage preserved within the Archaeological Park of Baratti and Populonia.
A project that continues a long-established tradition of study
The new excavation project follows in the footsteps of a long season of research on the Acropolis, carried out between the 1990s and 2000s by the then Archaeological Superintendency of Tuscany in collaboration with the Universities of Siena, Pisa, Roma Tre, and La Sapienza.
These investigations made it possible to redefine our understanding of the sacred area and its monumental buildings overlooking the main terrace of the ancient city.
The current research therefore continues this methodological and scientific tradition while also introducing a spirit of renewal: new techniques of documentation, digital surveying, and material analysis now allow us to critically reassess what is already known and to explore aspects of Populonia’s urban life that have so far remained little understood.
The new excavation areas
At the heart of the ArcheoPopulonia Project lies a building complex located behind Temple C, one of the main sacred structures of the Acropolis, which - together with Temples A and B - overlooks the public area situated in the saddle between Poggio del Telegrafo and Poggio del Castello.
The excavation campaigns of 2024 and 2025 have made it possible to complete the documentation of the complex, to understand its layout, purpose, and construction phases, and to restore to the city’s history a building of remarkable interest: a Republican-period bath complex, probably intended for public use.
The First Phase: a large monumental cistern
The first construction phase dates back to the first half of the 2nd century BCE.
During this phase, a large underground cistern was built, nearly 11 meters long and about 3,7 meters high, constructed with large squared blocks of calcarenite. The walls and barrel vault were coated with hydraulic mortar, an impermeable mixture that ensured water retention.
It is possible that even at this stage the area was intended for water-related use, perhaps as a small bath complex or a service building connected to the sacred area.
The transformation into a bath complex
In the second half of the 2nd century BCE, following the partial collapse of the cistern, the building was renovated.
This intervention marks the birth of a true balneum, that is, a small bath complex, organized into spaces for visitors and a service quarter.
The calidarium, the room intended for hot baths, is a large quadrangular space, paved with mosaics. The walls were covered with painted plaster in the First Pompeian style (I stile pompeiano), featuring a red dado and panels imitating marble slabs.
The room was equipped with a marble labrum, a round basin for individual ablutions. For collective baths a rectangular basin with waterproof plaster and a mosaic decoration was used.
The refinement of the decorations and the care in construction indicate a high-level building, likely intended for an urban public and not exclusively private use.
The heating system
The calidarium’s basin was heated by a praefurnium, that is, the furnace room, located at a lower level than the other spaces and incorporated into a porticoed structure.
The hot air, produced by the fire and pushed by bellows, traveled through a vaulted duct beneath the basin, while the smoke was evacuated through a chimney that crossed the adjoining room.
A system of lead pipes allowed cold water to be introduced into the building and then distributed to the different parts of the facility.
The water supply was ensured by a smaller cistern, built on the ruins of the older structure.
Overall, the complex represents a remarkable example of Republican-era hydraulic and thermal engineering, within a medium-sized urban context such as Populonia.
Crisis, abandonment, reuse
Perhaps in the middle decades of the 1st century BCE, during a period of general crisis for the city, the thermal complex underwent progressive abandonment.
The building was partially dismantled: the praefurnium was reused as a workshop for lead recycling, while part of the complex was repurposed for residential use.
A new and significant phase of occupation is recorded between the 9th and 11th centuries: during this period, the structures were incorporated into a medieval settlement, confirming the long continuity of life on the acropolis of Populonia, which remained a point of reference in the territory even after the end of the Roman city.
Towards new knowledge and new forms of enhancement
The research conducted within the ArcheoPopulonia Project is providing important scientific data on the introduction and development of thermal complexes in central Italy, as well as on the urban evolution of Populonia between the Republican and Imperial periods.
From a heritage enhancement perspective, the results open up the possibility of expanding the Archaeological Park’s visitor route, including the newly discovered areas of the acropolis and making structures of exceptional architectural and historical interest accessible to the public.
The goal is to offer visitors a more complete story of the ancient city: not only its temples and necropolises, but also the places of daily life, well-being, and social interaction.
