Delta landscapes, like China's Greater Bay Area (GBA), serve as gateways for economic and social integration. The GBA's "One Country, Two Systems" and multiple economic zones facilitate urbanization and global market integration. However, this development led to imbalanced ecology and fragmented development. Rural migration drained the countryside, and the polycentric model favored economic cores, marginalizing secondary areas reliant on low-skill manufacturing. Marginalized landscapes, including urban villages and peripheral towns, emerged with poor living conditions. To restore socio-ecological equilibrium, the GBA must adopt an urbanization model that harmonizes human activities with nature, creating a Necklace Metropolis. This involves enhancing connectivity, accessibility, multifunctionality, density, and environmental sustainability to revitalize marginalized areas.