This thesis investigates the challenges of transitioning from conventional grey infrastructure to nature-based flood defenses (NBFD) in coastal adaptation. It explores the concept of path dependency, where established practices, institutional structures, and systemic inertia hinder the adoption of innovative solutions. Through in-depth analysis of case studies in the Global North and South, the research identifies barriers, such as regulatory constraints and entrenched paradigms, that limit the feasibility of NBFD. It also highlights enablers, including community collaboration, integrated governance, and adaptive capacity-building. By comparing how these factors interact in different contexts, the study provides insights into overcoming institutional and systemic lock-ins. The findings offer practical recommendations for planners, policymakers, and practitioners seeking to implement NBFD as sustainable and resilient alternatives to traditional infrastructure. This work contributes to a broader understanding of how to navigate complex socio-political and ecological landscapes in adapting to the challenges of climate change.