The aim of this project was to evoke dialogue between family members about the content of the exhibition One Planet, an exhibition about global issues. One Planet is the main exhibition of the Museon and is based on the seventeen sustainable development goals of the United Nations. The project focused on families with children between 8-12, the main target group of Museon. Research on the current visitor experience showed that there is a lack of opportunity for families to reflect the content on their own daily lives, and to talk about the subjects. Besides, the exhibition did not sufficiently encouraged visitors to take actions to contribute to sustainable development. Literature research was done on two main themes: how to facilitate dialogue and reflection in a museum environment and how to promote sustainable attitudes and behavior. This resulted in a set of design principles that were used as guidelines during the design process. Dialogic participation was placed central to the development of the final concept. The final concept, Expedition One Planet, consists of thematic journeys through the exhibition and the surrounding exhibition rooms. A thematical focus enhances the learning experience as it provides guidance and introduces a goal for the visit. It gives visitors the opportunity to engage with, and discuss a subject for a longer time. An outline for the expeditions was created demonstrating the elements that are part of each expedition: a booklet, exploration boards, question boards and the end point where visitors can write down and share a sustainable challenge. The elements are the same, but the content differs per theme. One theme was elaborated to illustrate and test the concept. Eight families tested the design. The concept proved promising in providing a meaningful learning experience for both adults and children. Due to the thematical focus parents felt more motivated to explain information to their children and the activity stimulated the family members to explore the exhibition together instead of separately. The elements that included dialogic participation, the question board with a multiple choice question and writing a challenge, did stimulate visitors to reflect on their own behavior and to discuss the subjects with their family members. The sharing of challenges was seen as a potential source of information for sustainable behavior. Equally important, the elements of the expedition were perceived as enjoyable and interesting by the families. Further development is required, but the concept is feasible and has the ability to make visitors feel more involved in the global issues presented in One Planet.