The Hai River, also known as the Peiho, Pei Ho, or Hai Ho, is a Chinese river connecting Beijing to Tianjin and the Bohai Sea.

Tianjin is a municipality and metropolis in Northern China on the shore of the Bohai Sea. As such, it is not part of a province of China. It is one of the nine national central cities in Mainland China, with a total population of 13,866,009 inhabitants at the time of the 2020 Chinese census. Its metropolitan area, which is made up of 12 central districts, was home to 11,165,706 inhabitants and is also the world's 29th-largest agglomeration and 11th-most populous city proper.