The Symbiosis project aimed to address the growing challenge of eco-anxiety and promote mental health among youth and youth workers. By combining innovative methodologies such as nature-based learning, environmental education, and collective intelligence, the project sought to equip youth workers with tools to support eco-anxious individuals and foster sustainability in their communities. The objectives were to create learning opportunities for youth workers, design an inclusive methodology for addressing eco-anxiety, enhance diversity and inclusion in youth work, and increase the quality of nature-based learning and emotional agility practices. Additionally, the project aimed to strengthen European networks and build a shared identity around sustainability, inclusion, and mental well-being. Through these objectives, Symbiosis sought to empower individuals and organizations to tackle mental health and ecological challenges effectively.