Haimen is a district of Nantong, Jiangsu province. Located on the northern bank of the Yangtze River estuary, it faces Shanghai across the river. Renowned as the "Gateway to the Yangtze River and the Yellow Sea" and "Little-Pudong", the district covers about 1,149 square kilometers and had a permanent population nearly 1 million in 2025. With its coastline along the Yangtze and the Yellow Sea, Hai…