渤海
A medium-sized gulf, the Bohai Sea is enclosed by four provinces from three different regions of China — Liaoning (of Northeast China), Hebei and the Tianjin municipality (of North China), and Shandong (of East China). The whole of the Bohai Sea is considered part of both the internal waters of the People's Republic of China and the center of the Bohai Economic Rim. Its proximity to the Chinese capital of Beijing and municipality of Tianjin makes it one of the busiest seaways in the world.