The "Musée archéologique" (Archaeological Museum) is in the basement. The former archaeological collections of the city had been entirely destroyed, along with the municipal library, during the Siege of Strasbourg in 1870. A new collection was started in 1876 on behalf of the "Society for the preservation of the historical monuments of Alsace" (, ). It was moved into the palace in 1889, first opened to the public in 1896, and moved to its present location in 1907. The museum displays finds from northern Alsace from the Paleolithic Era to the Merovingian dynasty, with a special focus on Argentoratum.