CIUDADES BIODIVERSAS Y RESILIENTES. EL PLAN MAESTRO DE LETICIA EN EL AMAZONAS BIODIVERSE AND RESILIENT CITIES. LETICIA’S MASTERPLAN IN THE AMAZON.

This Special Issue documents the outcomes, methodology, and prospects of a collaboration between the Italian Agency for Development Cooperation (AICS) and the National Institute of Urban Planning (INU) aimed at rethinking urban planning in fragile contexts: the drafting of the Leticia Masterplan (2025-2026). Situated in the heart of the Amazon rainforest, where Colombia meets Brazil and Peru, Leticia is not merely a border city, but a unique urban organism that challenges traditional planning paradigms. This volume presents the work carried out within the Colombian national program “Ciudades Biodiversas y Resilientes” (Biodiverse and Resilient Cities), promoted by AICS and entrusted to INU, establishing itself as a model of international technical-scientific cooperation. Leticia exists in a state of perennial asynchrony between the rigidity of its colonial grid and the hydrogeological dynamism of the Amazon River. In this context, flood risk is not a statistical contingency, but a seasonal and identity-defining condition. This research assumes such fragility not as a constraint, but as the very foundation of the project. Moving beyond the reductionist approach that views nature as a limit to be contained, the Masterplan proposes an “urbanism of coexistence,” where biodiversity is elevated to primary infrastructure and the urban system adapts to fluvial cycles through amphibious and resilient solutions. The methodological framework is grounded in the convergence of urban planning, architecture, and social sciences, adopting the paradigm of Participatory Action Research (Par) and Research by Design. The process is not conceived as a top-down technical exercise, but as a reflective practice that transforms the co-production of knowledge into transformative action. . The Masterplan is structured into three circular and iterative phases: 1. interpretative knowledge and multiscalar diagnosis: analysis of the territory as a complex socio-ecological system, integrating technical knowledge and local perceptions; 2. strategic evaluation: definition of priorities in alignment with international frameworks (Paris Agreement, Sustainable Development Goals) and the urgent needs of the communities; 3. construction of an evolutionary scenario: conceived as an “open project,” capable of accommodating transformations over time and plural contributions, ensuring operational flexibility in conditions of uncertainty The intervention is articulated along key axes that redefine the cityriver relationship: the strengthening of green infrastructure, the redevelopment of the waterfront (the malecón) as an amphibious edge, and the consolidation of informal stilt-house fabrics. The beating heart of this strategy is the Parque Orellana, conceived as a “trigger project”: an urban resilience laboratory that transforms a marginal area into a space for ecological regeneration and cultural inclusion, mediating between global protection mandates and local needs for services and identity. A fundamental pillar of the process has been the early and constant involvement of the community. Participation has fostered a sense of social ownership of the Plan, recognizing the value of indigenous knowledge in resource management. This relational dimension extended beyond Leticia’s boundaries through Capacity Building activities conducted in Bogotá and San Andrés island as well. This Special Issue demonstrates how the Leticia Masterplan represents a crucial step toward a new urban design culture. By overcoming the separation between nature and the city, the Amazonian experience suggests that future planning must be an adaptive, symbiotic process deeply rooted in its territory.