Often, interfaces between cites and natural parks exhibit environmental degradation. Yet, their transitional character holds great potential for reconnecting citzens with nature. Similarly, the needs of people at transitional stages of life, such as the young and elderly, are often underrepresented in the public realm. ELDER NATURE bridges these challenges by integrating and enhancing the previous Elderly on Track and OPEN NATURE NEB projects to remediate a new boundary site in the Collserola Natural Park, central to the Metropolitan Area of Barcelona. Three newly combined target communities will be engaged and benefit: i] young public school students; ii] elderly persons from surrounding neighbourhoods; and iii] architectural master’s students. The Col·legi Montserrat school will be improved based on: i] insights from a foraging walk with the elderly and youths; ii] co-design with all target groups; and iii] advanced biobased installations by the master’s students. Contact with nature is essential for human health, wellbeing and quality of life, and is especially critical for the development of young people (Harvard Medical School). Still, many schools in urban and peri-urban areas do not have easy access to green spaces. Relatedly, Europe’s elderly population has suffered an increasing process of environmental and social disconnection since 2020. During the COVID-19 pandemic, 28.6% of older adults experienced loneliness and 31.2% social isolation, provoking an enduring disruption of elderly networks and their exclusion (Cambridge University). Fortunately, the 8000ha of forest within the Collserola Natural Park offer great prospects for re-connecting with nature, and with other people. Yet, the culture or habit of engaging with the park does not currently exist among many schools nor students, partly due to a lack of feelings of ownership or accessibility associated with a scarcity of well-designed transitional urban/natural spaces, as well as the progressive degradation of the park (La Vanguardia). On the other hand, elderly persons frequently visit the park to walk for leisure, exercise, socialisation, and to gather the numerous wild edible plants including various mushrooms, herbs, fruits, nuts and vegetables. ELDER NATURE learns from the tacit knowledge embedded in these foraging walks by applying the participatory methodology pioneered in 2022’s Elderly on Track (ElTra) project, which merges engagement and active mobility for elderly wellbeing. Furthermore, ELDER NATURE enhances these precedents through integration with the methodology developed in 2022’s OPEN NATURE project of realising public green space preservation and regeneration measures through the participation of young students, alongside master’s students. In this way, ELDER NATURE innovates an even more inclusive, multigenerational engagement process simultaneously benefiting three target groups as a novel collaborative community. Moreover, ELDER NATURE will enhance the value of sustainability by addressing the key topic of local food production. This will be achieved by improving the site of Col·legi Montserrat in Valvidrera, a village on the edge of Barcelona, based on insights regarding resilient, nutritious and delicious plant species gained from the foraging walks. Improvements will be implemented through co-design with all target groups, resulting in beautiful, advanced, biobased installations by IAAC’s master’s students following the NEB Compass.