Seoul, officially the Seoul Special City, is the capital and largest metropolis of South Korea. Seoul has a population of 9.7 million people, and forms the heart of the Seoul Capital Area with the surrounding Incheon metropolis and Gyeonggi province. Seoul was the world's 4th largest metropolitan economy in 2014 after Tokyo, New York City and Los Angeles. In 2017, the cost of living in Seoul was ranked the 6th highest globally.
Settlement of the Han River area, where present-day Seoul is located, began around 4000 BC.
Seoul is first recorded as Wiryeseong, the capital of Baekje (founded in 18 BC) in the northeastern area of modern Seoul. There are several city walls remaining in the area that date from this time. Pungnaptoseong, an earthen wall located southeast Seoul, is widely believed to have been at the main Wiryeseong site. As the Three Kingdoms competed for this strategic region, control passed from Baekje to Goguryeo in the 5th century, and from Goguryeo to Silla in the 6th century.
In the 11th century Goryeo, which succeeded Unified Silla, built a summer palace in Seoul, which was referred to as the "Southern Capital". It was only from this period that Seoul became a larger settlement. When Joseon replaced Goryeo, the capital was moved to Seoul (also known as Hanyang or Hanseong), where it remained until the fall of the dynasty. The Gyeongbok Palace, built in the 14th century, served as the royal residence until 1592. The other large palace, Changdeokgung, constructed in 1405, served as the main royal palace from 1611 to 1872. After Joseon changed her name to the Korean Empire in 1897, Hwangseong also designated Seoul.
Originally, the city was entirely surrounded by a massive circular stone wall to provide its citizens security from wild animals, thieves and attacks. The city has grown beyond those walls and although the wall no longer stands (except along Bugaksan Mountain (Korean: 북악산; Hanja: 北岳山), north of the downtown area), the gates remain near the downtown district of Seoul, including most notably Sungnyemun (commonly known as Namdaemun) and Heunginjimun (commonly known as Dongdaemun). During the Joseon dynasty, the gates were opened and closed each day, accompanied by the ringing of large bells at the Bosingak belfry. In the late 19th century, after hundreds of years of isolation, Seoul opened its gates to foreigners and began to modernize. Seoul became the first city in East Asia to introduce electricity in the royal palace, built by the Edison Illuminating Company and a decade later Seoul also implemented electrical street lights.
Much of the development was due to trade with foreign countries like France and the United States. For example, the Seoul Electric Company, Seoul Electric Trolley Company, and Seoul Fresh Spring Water Company were all joint Korean–U.S. owned enterprises. In 1904, an American by the name of Angus Hamilton visited the city and said, "The streets of Seoul are magnificent, spacious, clean, admirably made and well-drained. The narrow, dirty lanes have been widened, gutters have been covered, roadways broadened. Seoul is within measurable distance of becoming the highest, most interesting and cleanest city in the East."
After the annexation treaty in 1910, Japan annexed Korea and renamed the city Gyeongseong ("Kyongsong" in Korean and "Keijo" in Japanese). Japanese technology was imported, the city walls were removed, some of the gates demolished. Roads became paved and Western-style buildings were constructed. The city was liberated by U.S. forces at the end of World War II.
In 1945, the city was officially named Seoul, and was designated as a special city in 1949.
During the Korean War, Seoul changed hands between the Soviet/Chinese-backed North Korean forces and the American-backed South Korean forces several times, leaving the city heavily damaged after the war. The capital was temporarily relocated to Busan. One estimate of the extensive damage states that after the war, at least 191,000 buildings, 55,000 houses, and 1,000 factories lay in ruins. In addition, a flood of refugees had entered Seoul during the war, swelling the population of the city and its metropolitan area to an estimated 1.5 million by 1955.
Following the war, Seoul began to focus on reconstruction and modernization. As South Korea's economy started to grow rapidly from the 1960s, urbanization also accelerated and workers began to move to Seoul and other larger cities. From the 1970s, the size of Seoul administrative area greatly expanded as it annexed a number of towns and villages from several surrounding counties.
Until 1972, Seoul was claimed by North Korea as its de jure capital, being specified as such in Article 103 of the 1948 North Korean constitution.
According to 2012 census data, the population of the Seoul area makes up around 20% of the total population of South Korea, Seoul has become the economic, political and cultural hub of the country, with several Fortune Global 500 companies, including Samsung, SK Holdings, Hyundai, POSCO and LG Group headquartered there.
Seoul was the host city of the 1986 Asian Games and 1988 Summer Olympics as well as one of the venues of the 2002 FIFA World Cup.
Seoul is in the northwest of South Korea. Seoul proper comprises 605.25 square kilometres (233.69 sq mi), with a radius of approximately 15 km (9 mi), roughly bisected into northern and southern halves by the Han River. The Han River and its surrounding area played an important role in Korean history. The Three Kingdoms of Korea strove to take control of this land, where the river was used as a trade route to China (via the Yellow Sea). The river is no longer actively used for navigation, because its estuary is located at the borders of the two Koreas, with civilian entry barred. Historically, the city was during the Joseon dynasty bounded by the Seoul Fortress Wall, which stretched between the four main mountains in central Seoul: Bugaksan, Inwangsan, Naksan and Namsan. The city is bordered by eight mountains, as well as the more level lands of the Han River plain and western areas. Due to its geography and to economic development policies, Seoul is a very polycentric city. The area that was the old capital in the Joseon dynasty, and mostly comprises Jongno District and Jung District, constitutes the historical and political center of the city. However, for example, the city's financial capital is widely considered to be in Yeouido, while its economic capital is Gangnam District.
Seoul has a humid continental climate influenced by the monsoons (Köppen: Dwa). Being in the extreme east Asia, the climate can be described as humid subtropical with great variation in temperature and precipitation throughout the year. (Cwa, by -3 °C isotherm). The suburbs of Seoul are generally cooler than the center of Seoul because of the urban heat island effect. Summers are hot and humid, with the East Asian monsoon taking place from June until September. August, the hottest month, has average high and low temperatures of 32.6 and 23.4 °C (91 and 74 °F) with higher temperatures possible. Heat index values can surpass 40 °C (104.0 °F) at the height of summer. Winters are quite short but usually cold to freezing with average January high and low temperatures of 1.5 and −5.9 °C (34.7 and 21.4 °F), and are generally much drier than summers, with an average of 24.9 days of snow annually. Sometimes, temperatures drop dramatically to below −10 °C (14 °F), and on some occasions as low as −15 °C (5 °F) in the mid winter period of January and February. Temperatures below −20 °C (−4 °F) have been recorded.
