Birs

Bersia (“the one that flows swiftly”) is the Celtic name of the river that rises near Tavannes in the Bernese Jura Mountains and flows into the Rhine after 73 km. The spectacular river valley crosses the fold mountains of the Jura in eight narrow gorges, and has been considered a tourist attraction since the 18th century. The Birs was not navigable due to the many rapids and waterfalls; however, it was actively used by raftsmen. In addition, the road alongside the river was the most important connecting route for traffic in the former prince-bishopric of Basel, which stretched from the Rhine to Lake Biel.
At Münchenstein, the Birs entered its natural floodplain area. It flowed through the Brüglingen Plain in highly sinuous meanders and branched into several tributaries. Only the major corrections of the Birs between 1814 and 1823 forced it into its present riverbed on the southern edge of the Brüglingen Plain.

Image: Course of the banks of the Birs according to Jakob Meyer 1657 (from: E. Golder “Die Birs”)