Introduction to Shuangyu Port: Shuangyu Port is located between Fodu Island and Liuheng Island outside the Meishan Salt Fields in Beilun. During the Ming Dynasty, it was under the jurisdiction of Guo Juqianhu, Dinghai County (now Zhenhai), Ningbo Prefecture, and now it belongs to Zhoushan Municipal jurisdiction. Syongicam is Shuangyu Ocean, now called Shuangyu Gate, which is the name of the waterway. Shuangyuyang is the only channel for entering and exiting the Yongjiang River in Ningbo, and is the trade gate of Ningbo. Shuangyu Port is suspended in the ocean and is on the main channel line, but it is not far from the coast and is convenient for food and grass supply. It was a very prosperous private trade port 500 years ago and was also a frequent place for smuggling trade.