Archaeologists in Switzerland have discovered the remains of a late Roman wooden bridge beneath the waters of the Aare River near Solothurn, providing the first direct archaeological evidence of a long-suspected river crossing linked to the ancient Roman settlement of Salodurum.
The discovery was made during an underwater archaeological survey ahead of renovation on an SBB railway bridge spanning the river. Divers working on behalf of the cantonal archaeology department discovered a series of ancient timber piles embedded in the riverbed just upstream from Solothurn’s Wengi Bridge.
Wood samples taken from the submerged structures have now been scientifically dated to the fourth century AD, suggesting the remains belonged to a bridge in the Late Roman period.
Based on the recent research, the findings could constitute a major breakthrough in the understanding of the Roman infrastructure of the region and finally bring to light decades of speculation about a crossing at the site.
Archaeologists had long suspected that the Romans maintained a bridge near Solothurn because of the strategic geography of the area and its position along an important transalpine trade and military route. The new bridge formed part of a Roman road that linked northern Italy to the Rhine frontier, crossing the Great St Bernard Pass and then passing through the western Swiss Plateau and Jura Mountains.
The traces of the ancient road had already been found between Büren an der Aare and Nennigkofen at some point, but until now no physical evidence of the river crossing had ever been found, at least not at this point.
The bridge’s location appears to have been carefully chosen. Upstream from Solothurn, the Aare River narrows sharply as it winds through the landscape, creating a natural bottleneck that would have provided an ideal crossing point for travellers, merchants and soldiers.
Even the ancient name of the settlement reflects this geography. Salodurum— the Roman name for Solothurn— comes from a Celtic field name believed to mean “river narrows” or “wave gate” and supports the long-held belief that there was once a crossing there.
The newly uncovered remains include several substantial wooden piles firmly anchored in the riverbed. About ten metres from the southern bank, archaeologists found a line of piles stretching downstream. The timbers, some of them nearly two metres in length, were thought to form part of a bridge pier, called a pile yoke, that would have supported the road above.
During the 1969 Jura water correction works, many sections of the riverbed around Solothurn were dredged, a process that could easily have destroyed the remains. But the ancient piles survived, apparently protected beneath the Wengi Bridge.
The current construction of the new railway bridge will also leave the Roman remains untouched. Because waterlogged conditions save the ancient wood from rapid decay as it gets exposed to air, the timbers are best preserved while submerged, archaeologists said.
Divers will continue to investigate the riverbed during future operations in order to discover additional parts of the Roman bridge..
Archaeologists hope that the submerged remains will help to shed light on how the bridge was built and how it functioned in a Roman transport network in the Mediterranean world and in northern Europe.
Sources : Canton of Solothurn
