Tianjin (/tjɛnˈtʃiːn/;[6] Chinese: 天津; pinyin: Tiānjīn; Mandarin: [tʰjɛ́n.tɕín] (listen)), 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 estimated at 15,621,200 in 2016.[7] Its built-up (or metro) area, made up of 12 central districts (all but Baodi, Jizhou, Jinghai and Ninghe), was home to 12,491,300 inhabitants in 2016 and is also the world's 29th-largest agglomeration (between Chengdu and Rio de Janeiro) and 11th-most populous city proper.[8]