Tianjin, alternately romanized as Tientsin, is a municipality and a coastal metropolis in Northern China on the shore of the Bohai Sea. It is one of the nine national central cities in Mainland China, with a total population of 13,866,009 inhabitants during the 2020 Chinese census. Its built-up area, 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.