This paper discusses the experimental set up of MUSE, an interactive and mobile fruition system, at a primary Italian museum, La Certosa e Museo di San Martino located inside a large and marvelous XIV century charterhouse on the Vomero Hill in Napoli. System integration, as well as content design and fruition goals are addressed. The system is going to be demonstrated in a museum section called Immagini e Memorie della Città (“Images and Memory of the Town”). This section was chosen because, with its links to the city and its history, and with its views over the real modern city, it offers a good opportunity to verify MUSE educational and entertainment potential. The paper shows with examples how MUSE mobile device (called Whyre“) transfers knowledge, relating the artistic abstraction with the reality, and providing the visitor with a dual perception level of the city, one on its past history and one on its present life.