Territorial regeneration can be an opportunity for enhancing mountain valleys in the Anthropocene, hit by the trans-scale pandemic, economic, and environmental polycrisis. Mountain territories can be re-developed through community-based approaches for the regeneration of brownfields present in their valleys—previous industrial areas abandoned because of economic recession—that can become starting points for new green policies. These regenerating sustainable interventions can be co-designed, with the orchestration of universities in a communitarian perspective, implying Local Government—such as Municipalities and their aggregating Institutions like Mountain Communities or LAG-Local Action Groups of the EU-LEADER Strategy, or Provinces and Regions - together with private actors, associations, as well as residents, commuters, migrants, and tourists, to strengthen pro-environmental behaviours in everyday life (health, educational, or mobility services), and to answer, at the same time, to cultural and leisure needs (art, sport, recreation, and so on). Therefore, mountain valleys can become challenging places for soil restitution to inhabitants, creating new job opportunities based on sustainable tourism as a green activity integrated with other territorial functions, practices, and knowledge, for thinking of new ways of living in a trans-scale perspective. This approach can be applied to Lombard valleys, in Italy, that were affected by environmental, economic, and pandemic crises. These valleys are interesting case studies as they host many brownfields, they preserve traditional productive activities, and, after the pandemic, they launched more touristic places in a green perspective. Therefore, a community-based approach for brownfields regeneration can be guided by universities as orchestrators of cultural and territorial innovation in strict connection with Local Governments to co-design new ways of living.