Yingkou is a prefecture-level city of Liaoning province, in northeastern China. It is a port city of the Bohai Sea. The Liao river (Liao He) goes to the sea at Yingkou. The city has a total area of 4,970 square kilometers, and a population of 2,428,534 at the 2010 census. Yingkou was formerly known as Newchwang - one of the Treaty Ports opened under the Treaties of Tianjin of 1858. In fact the town of Newchwang was about thirty miles upstream of Liao He. After the treaty had been signed, the British found that the river near Newchwang was too shallow for their ships. Instead, the treaty port was moved to the area nearer to the river mouth where today's Yingkou is located.