Teenagers are an understudied group within the Interaction Design and Children community. Museums and cultural heritage spaces offer solutions for young children but do not target teenagers in particular. Teens, are a large pool of potential museum audiences. They should be given a "voice" and involved early in the design process to maximize chances of involvement in the museum practices and offers, hence, it is crucial to study their interests and desires to deploy a high quality and enjoyable product. For these reason, we deployed several co-design sessions with a total of 155 teenage participants, in order to understand how would they prefer to engage with museum tours. The authors, based on Madeira island (Portugal), used the Natural History Museum of Funchal as a case study. The participants were asked to ideate a mobile museum experience that they would enjoy. Through qualitative analysis, we gathered insights regarding six main themes that they reported as prompts in order to visit the Natural History Museum of Funchal, such as 1) gaming, 2) interactions, 3) localization, 4) social media, 5) aspects of the museum studied, and 6) photos. These findings are preliminary and still need testing and validation.