Beijing, alternatively romanized as Peking, is the capital of the People's Republic of China. It is the world's most populous national capital city, with over 21 million residents within an administrative area of 16,410.5 km². Nevertheless, its built-up area, the third largest in China after Guangzhou and Shanghai, is slightly bigger, including three districts in Hebei being conurbated but with Miyun and Pinggu Districts in Beijing not agglomerated yet. It is located in Northern China, and is governed as a municipality under the direct administration of the State Council with 16 urban, suburban, and rural districts. Beijing is mostly surrounded by Hebei Province with the exception of neighboring Tianjin to the southeast; together, the three divisions form the Jingjinji megalopolis and the national capital region of China.