The Local Activity Lab is a project carried out by three organisations forming the Active City Collective in three neighbourhoods of the City of Poznan: Główna, Wilda and Dębiec. Its aim is to increase social activity and the sense of influence of these neighborhoods’ residents on the development of their immediate environment. As part of the project, we are setting up a group of local leaders (in particular youth and young adults), who will become involved in decision-making processes concerning the appearance and functionality of the space in the three neighborhoods. We are creating a development programme for the residents on environmental protection, ecology and local sustainability. We are carrying out a series of expert workshops and consultations, including conducting a diagnosis of the resources and problems of public space in the context of urban ecology, green and blue infrastructure development, rivers and riparian areas in the neighbourhoods. Next, the leaders will design and construct green common spaces, implement ecological initiatives in their neighbourhoods, run a social campaign addressing one of the diagnosed problems, and submit a joint project to the City of Poznan’s Participatory Budget. The project will be summarised in a publication – a notebook of good practices.