The reason why a large number of Koreans gather in Seoul is simple, because it is the most promising place in South Korea. South Korea's central government, parliament, the Supreme Court and other political institutions are all in Seoul; Seoul National University, Korea University, Yonsei University, Sungkyunkwan University, dongguk university, Xijiang University and other outstanding educational institutions are in Seoul; Cultural institutions such as Chosun Ilbo, East Asia Daily, Central Daily and major publishing houses are all in Seoul. Most chaebol and factories are also concentrated in Seoul.

Most cities around Seoul were annexed, such as Guan Yue City, Gyeonggi Province, Guan Yue District of Seoul, Shixing County of Gyeonggi Province and Luanchuan District of Seoul. Or it is upgraded to a city because of the population increase (a large number of working-class people who can't afford Seoul's housing prices flood into the surrounding area). For example, part of Guangzhou County of Gyeonggi Province was divided into South City of Gyeonggi Province, and part of Yangzhou County of Gyeonggi Province was divided into South Yangzhou City of Gyeonggi Province.

These satellite cities are different from Tongzhou in Beijing and Tsuen Wan in Kowloon. These are cities with relatively perfect urban construction.