Résumé : Parks hold great potential for promoting healthy ageing, however, older adults are underrepresented among park visitors, indicating that current park designs may not adequately meet their needs and preferences. This may be explained by older adults often being excluded from planning and development processes for urban green spaces. This participatory study involved older adults living in low-income neighbourhoods in a stepped park design process for redeveloping an urban park in Belgium. The study (1) identifies social and physical park features that were perceived as important to and desired by older adults to promote park visitation, park-based physical activity, social interaction and relaxation and (2) explores the specific designs older adults prefer for the identified physical park features. The study comprised three parts: (1) establishing an action group of older adult citizen scientists, (2) walk-along interviews, and (3) focus group interviews. Results indicated that bench heights higher than standard and with arm and back-supports, accessible and safe walking paths, a range of exercise facilities, shade and shelter, a variation of trees, plants and flowers, and a water feature were most important to and desired by older adults. The participatory process is thoroughly detailed in this paper. The results of this study are important to urban planners, architects, city councils, and policy makers and can inform future participatory design processes and park (re)design.