The International Guidelines on Natural and Nature-Based Features for Flood Risk Management emphasize the role of nature-based solutions and natural infrastructure (e.g., beaches, dunes, islands, marshes) as an alternative to conventional hardened infrastructure for flood and coastal storm risk reduction and represents the state of the science on conceptualizing, planning, designing, engineering, implementing and maintaining NNBF. The Guidelines will equip decision-makers, project planners, and practitioners with strategies that reduce flood risks to communities and improve infrastructure resilience. The document is organized so readers can begin where their interests lie. The chapters were developed in a collaborative environment where there was communication and engagement across chapter teams. Each chapter begins with a list of its key, high-level messages, includes references to other chapters, and uses icons and case studies to draw attention to key topics covered elsewhere in the Guidelines.