The Aquarium-Museum is an unusual institution that combines a freshwater aquarium with collections related to zoology and mineralogy. The aquarium section focuses on the fish of Lorraine's rivers — trout, pike, carp — alongside a good display of tropical species. The natural history collections upstairs are less spectacular but include some fine mineral specimens.
It is a good option for a morning when other sites are closed, or for visitors with children. The aquarium is popular with school groups during the week but generally quieter at weekends. It sits in the university quarter, a short walk from the botanical garden and the Musée de l'École de Nancy.