Beijing, (/beɪˈdʒɪŋ/) formerly romanized as Peking, is the capital of the People's Republic of China and the world's second most populous city proper and most populous capital city. The city, located in northern China, is governed as a direct-controlled municipality under the national government with 16 urban, suburban, and rural districts. Beijing Municipality is surrounded by Hebei Province with the exception of neighbouring Tianjin Municipality to the southeast; together the three divisions form the Jingjinji metropolitan region and the national capital region of China.
As a city combining both modern and traditional architecture, Beijing is an ever-changing megacity rich in history but also truly modern, exemplified in its global influence in politics, business & economy, education, history, culture, language, music, sporting, architecture, civilization, fashion, art, entertainment, innovation, and technology. Beijing is the second largest Chinese city by urban population after Shanghai and is the nation's political, cultural, and educational center. It is home to the headquarters of most of China's largest state-owned companies and is a major hub for the national highway, expressway, railway, and high-speed rail networks. The Beijing Capital International Airport has been the second busiest in the world by passenger traffic since 2010, and, as of 2016, the city's subway network is the busiest and second longest in the world, after Shanghai's subway system.
The city's history dates back three millennia. As the last of the Four Great Ancient Capitals of China, Beijing has been the political center of the country for much of the past eight centuries. With mountains surrounding the inland city on three sides, in addition to the old inner and outer city walls, Beijing was strategically poised and developed to be the residence of the emperor and thus was the perfect location for the imperial capital.