This thesis describes a research and design in how to engage millennials around the collection of the Fotomuseum. For the Fotomuseum to shift from a traditional institution to an open and social environment, the public should be involved. Involving the public is necessary to create a high-quality visitor experience. Extensive literature and empirical studies were conducted in different domains; the Fotomuseum, millennials, participatory and engaging museum principles. The holistic approach resulted in a starting point for developing a framework for an overarching social museum activity. Within this framework, the four core-elements socialization, meaning-making, escapism and interaction are integrated on the  visitor museum experience. The resulting design framework for an overarching social museum activity consists of a model for designing open-ended activities encouraging social interactions and prolong the experience outside the museum’s walls. A narrative architecture presents six different narrative spaces to activate participation and engage millennials around the collection on-site. In addition to these two models, thirteen design principles were formulated. The formulated design goal accompanied by an experience vision functioned as a starting point for the design process. In addition to individual designing, different co-creation and evaluative sessions were organized resulting in a concept proposal for an overarching social museum activity: Photo Studio. Photo Studio offers millennials an active and memorable experience at the Fotomuseum, inviting them to explore and use the collection for developing one’s mini-exhibition. The platform allows visitors to explore co-produced exhibitions at home, which highlights the museum as an open, essential and social place. The activity supports and encourages individuals to collaborate in creative activities in a larger social experience. One could see the concept as a vehicle for maintaining social relationships as well as a process for personal meaning-making. Throughout the journey the link between photographers and millennials is addressed, allowing visitors to reflect the world as they see it and engage with each other around photos. Six different stages are described that moves the visitor towards developing one’s Photo Studio. With an application and three different interactive exhibits, visitors can select photos from the archive, edit them in the darkroom and construct their own visual story in the interactive exhibits space. Each interactive exhibit is designed with personal entry points and tools for creative expression to engage with each other socially. Finally, visitors can view their Photo Studio anytime, anywhere as the platform provides a replica in an interactive 360-view. The concept was tested with 16 participants in a simulated environment and seven different prototypes. Based on the insights, the overarching activity is presumably found to facilitate the desired engaging experience for millennials. All of the 16 participants positively reviewed Photo Studio. Each group developed discussions around photos, collaboratively discovering new perspectives. The activity was reviewed as fun, active and motivating.