Water: metaphor for a healing element or symbol of a destructive primal force? In the works of Art Nouveau, breathtaking, rolling waves, fish, jellyfish, and mussels or creatures from mythological stories give rise to a space for the imagination that fulfills people's desires and dreams on the one hand and makes one shudder as a mysterious parallel world on the other. Water as a place of longing is presented by means of 250 works: Japonesque-like works, the dazzling ceramics of a Émile Gallé, and somber mythological paintings like that of the German artist Fidus visualize the idea of a total work of art with incredible diversity. Light is thus shed on the topic of "water in Art Nouveau" from an international, regional, and interdisciplinary perspective: for instance with a view to literature, music, or historical contexts.