Langfang (Chinese: 廊坊; pinyin: Lángfáng), is a prefecture-level city of Hebei province formerly known as Tianjin Prefecture until 1973, it was renamed Langfang Prefecture after Tianjin became a municipality and finally upgraded into a prefecture-level city in 1988, located approximately midway between Beijing and Tianjin. At the 2010 census, its population was 4,358,839 whom 868,066 lived in the built-up (or metro) area made of Guangyang and Anci districts. Its total area is around 6,417.28 km² (2,477.73 sq mi). Langfang borders Baoding to the southwest, Cangzhou to the south (both prefecture-level cities of Hebei), Beijing to the north and Tianjin to the east. Sanhe City and Dachang Hui County are now conurbated with Beijing belonging to the same built-up area.