This chapter presents the value and role of playfulness in its bodily and sensory aspects for the design of activities and interventions situated in urban spaces and aimed at public enjoyment and ageing well. Playful design, the mapping of playful experiences from games or toys to other non-game-context experiences, has gained interest in recent years. The chapter also presents a single case study which has employed playful design to engage older people in taking exercise and co-creating with other people. Two proof-of-concept prototypes were realized to illustrate the possibilities of playfulness in engaging people with physical activity in public urban spaces and to explore how it could be used and implemented in public urban environments. The first prototype was constructed with a mobile Near Field Communication interface and a conductive touch interface based on a MaKeyMaKey4 microcontroller. The second prototype was developed based on the feedback received from the testing of the first.