Located on the right bank of the Rhône, around 6 km from Valence, the commune of Soyons has been the subject of archaeological research that has demonstrated continuous occupation from the Palaeolithic to the medieval period, both on the plain and on the high ground of Malpas. For the ancient period, elements of an urban grid organized around a road and remains of dwellings have been recorded beneath the current village and its outskirts. All these elements help to identify Soyons as an ancient secondary settlement. However, this is the first preventive excavation to be carried out in the commune. The 920 m2 parcel concerned by this operation is located outside the presumed agglomeration.
The spa complex
The layout of the remains uncovered reveals an incomplete complex of imposing masonry, basins and hydraulic structures. Three areas could be defined, with at least six basins identified.These vary in size, from 4 m2 to 24 m2 for the largest. They are laid out with tile mortar, and are undoubtedly ornamented, as a fragment of a marble plaque can still be seen on the floor of one of them. In one of the basins, a bench was built around the perimeter.
Water was drained through terracotta pipes set into the walls or through masonry gutters installed under the baths.
A more monumental hydraulic structure, with a vaulted passage installed between two walls, could be designed to evacuate a more substantial flow of water. A number of features were added to prevent rising damp in the adjacent masonry (hydraulic mortar beads, foundation protrusions). This may have been necessary to drain water from the residential part of the villa above.
The wastewater drainage system converges on a collector, built between two masonry structures that also served as terrace walls. The preserved height of this structure is impressive, at 1.72 m.
Terracotta pipes were laid to drain the plot and evacuate run-off water. These are formed by two imbrices (semi-cylindrical hollow tiles) one on top of the other, forming a drainage channel. The collected water then flows into a "main" gutter, where spring water was still circulating at the time of the archaeological work, indicating that the ponds were used for pleasure and not for handicrafts.
An elaborate wastewater management system, based on a number of hydraulic features and a spring, has been set up here.
Another example of perfect water management is the placement of a dolium base (large jar) in a masonry mass that was probably used to collect run-off water from the roof of this bathing complex. A hole is drilled in its belly to allow water to drain away, which then flows into a small masonry channel connected to the main gutter.
While drainage systems are well documented, there are no water supply systems here. We have no clues as to how these basins were filled. However, an iron fitting for a wooden pipe has been uncovered. It’s conceivable that there were installations upstream from the site, taking advantage of the presence of a spring to direct water to the bathing facilities.
Although the small size of the excavation and the site’s dismantled state make it impossible to reconstruct the layout of the baths, we can assume that this is the cold zone. Piles of hypocausts and pipework were uncovered in a secondary context, but the praefurnium (the room with the furnace used to heat the hot and warm rooms) was not precisely located. Although located on the outskirts of the presumed ancient settlement, but on a site with a privileged view of the Rhone, this complex yielded numerous elements of comfort (painted plaster, marble, instrumentum), perhaps indicating the special status of this equipment.
Furnishing : Individual
Scientific supervision: Service régional de l’archéologie (Drac Auvergne Rhône-Alpes)
Scientific manager: Delphine Béranger, Inrap
