Transmedia storytelling is a narrative strategy often used to enhance and augment storytelling for audio-visual productions, such as television series or movies, as well as other media, and has long been studied and analyzed as a symptom of the entertainment industry. This chapter analyses the transmedia productions in the field of cultural heritage in France and explores the beginning of the design and creative process of an exemplary project. The introduction of new technologies in media practices has favored the expansion of transmedia storytelling. Forms of augmented narration, such as transmedia storytelling, are combined with traditional forms of mediation, in museums particularly, such as guided tours, mobile applications or interactive objects. In France two huge projects used transmedia storytelling and were focused on two iconic monuments: the Cathedral of Strasbourg and the Pantheon in Paris. Historic figures have been the center of transmedia strategies in order to highlight a specific period of French history.