The Sinuiju Yalu River Estuary Nature Reserve is a significant natural habitat situated at the boundary between North Korea and China, near the city of Sinuiju, which serves as the capital of North Pyongan Province. Encompassing an area where the Yalu River meets the Yellow Sea, the reserve is a critical stopover for many migratory birds, including rare species such as the black-faced spoonbill. The estuary's wetlands provide a rich feeding ground for these birds and support a diverse ecosystem, which includes fish and various plant species endemic to the saline-alkaline environment. Amid the marshes and the reed beds, it's not only a center for biodiversity but also a natural filter for the environment. Due to its ecological value, the site is considered important for conservation efforts, and it plays a vital role in international biodiversity as part of the flyway network of migratory birds. The contrast between the industrial cityscape of Sinuiju and the natural beauty of the estuary offers a unique perspective on the coexistence of urban development and natural preservation.