Jing-Jin-Ji in the context of "Baoding"

Beijing, previously romanized as Peking, is the capital city of China. With more than 22 million residents, it is the world's most populous national capital city, as well as China's second largest city by urban area, after Shanghai. 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 and neighbors Tianjin to the southeast; together, the three divisions form the Jing-Jin-Ji cluster.

Beijing is a global city and one of the world's leading centres for culture, diplomacy, politics, finance, business and economics, education, research, language, tourism, media, sport, science and technology, transportation, and art. It is home to the headquarters of most of China's largest state-owned companies and houses the largest number of Fortune Global 500 companies in the world, as well as the world's four biggest financial institutions by total assets. It is also a major hub for the national highway, expressway, railway, and high-speed rail networks. For a decade before the COVID-19 pandemic, Beijing Capital International Airport was Asia's busiest airport (2009–2019) and the second busiest airport in the world (2010–2019). In 2020, the Beijing subway was the fourth busiest and second longest in the world. Beijing Daxing International Airport, Beijing's second international airport, is the largest single-structure airport terminal in the world. The city has hosted numerous international and national sporting events, the most notable being the 2008 Summer Olympics and 2008 Summer Paralympics Games. In 2022, Beijing became the first city ever to host both the Summer and Winter Olympics, and also the Summer and Winter Paralympics.

Tianjin is a major international port city in China. It is a direct-administered municipality on the shore of the Bohai Sea making it separate from the surrounding Hebei province. It is one of the nine national central cities, with a total population of 13,866,009 inhabitants at the time of the 2020 Chinese census. Its metropolitan area, which is made up of 12 central districts (other than Baodi, Jizhou, Jinghai and Ninghe), was home to 11,165,706 inhabitants in 2015 and is also the world's 29th-largest agglomeration (between Chengdu and Rio de Janeiro) and 11th-most populous city proper.

Tianjin is governed as one of the four municipalities (alongside Beijing, Shanghai, and Chongqing) under the direct administration of the State Council of China. However, it is the only municipality with a population of less than 20 million. The city borders Hebei Province and Beijing Municipality, bounded to the east by the Bohai Gulf portion of the Yellow Sea. Part of the Bohai Economic Rim, it is the largest coastal city in Northern China and part of the Jing-Jin-Ji megapolis.