Sister cities of Seoul

Seoul (English pronunciation: /soʊl/; Korean: [sə.ul] — officially the Seoul Special City — is the capital and largest metropolis of South Korea. A megacity with a population of more than 10 million, it is the largest city proper in the developed world. The Seoul Capital Area, which includes the surrounding Incheon metropolis and Gyeonggi province, is the world's second largest metropolitan area with over 25.6 million people, home to over half of South Koreans along with 632,000 international residents.

Situated on the Han River, Seoul's history stretches back more than 2,000 years when it was founded in 18 BC by Baekje, one of the Three Kingdoms of Korea. It continued as the capital of Korea under the Joseon Dynasty and the Korean Empire. The Seoul metropolitan area contains four UNESCO World Heritage Sites: Changdeok Palace, Hwaseong Fortress, Jongmyo Shrine and the Royal Tombs of the Joseon Dynasty. Seoul is surrounded by mountains, the tallest being Mt. Bukhan, the world's most visited national park per square foot. Modern landmarks include the iconic N Seoul Tower, Lotte World, the world's second largest indoor theme park, and Moonlight Rainbow Fountain, the world's longest bridge fountain. The birthplace of K-pop and the Korean Wave, Seoul was voted the world's most wanted travel destination by Chinese, Japanese and Thai tourists for three consecutive years in 2009–2011 with over 10 million international visitors in 2012.

Today, Seoul is considered a leading and rapidly rising global city, resulting from an economic boom and growth known as the Miracle on the Han River which transformed it from the ashes of the Korean War to the world's fourth largest metropolitan economy with a GDP of US$773.9 billion in 2012 after Tokyo, New York City and Los Angeles. A world leading technology hub, it boasts the world's sixth largest number of Fortune Global 500 multinationals such as Samsung, the world's largest technology company, as well as LG, SK, and Hyundai-Kia. Gangnam is the commercial center along with Yeoui Island forming the financial center and Digital Media City being the technology hub. Jongno and Central District are the historical and cultural center of Seoul. Ranked sixth in the Global Power City Index, the metropolis exerts a major influence among global affairs as one of the five leading hosts of global conferences. It is one of the world's most livable major cities, with the United Nations rating Seoul's quality of life higher than New York City, London or Melbourne in 2012.

Seoul has a very technologically advanced infrastructure. It has the world's highest fibre-optic broadband penetration, resulting in the world's fastest internet connections with speeds up to 1 Gbps. Seoul Station is the main terminal of the KTX high-speed rail and the Seoul Subway is the world's largest subway network by length, considered the world's best subway by Jalopnik featuring 4G LTE, WiFi, DMB and WiBro. Seoul is connected via AREX to Incheon International Airport, rated the world's best airport seven years in a row (2005–2012) by Airports Council International. Lotte World Tower, a 556m (1,824 ft) supertall skyscraper is under construction in Seoul to become the OECD's tallest in 2015 with the world's tallest observation deck on its 123rd floor.

Seoul hosted the 1986 Asian Games, 1988 Summer Olympics, 2002 FIFA World Cup and the 2010 G-20 Seoul summit. A UNESCO City of Design, Seoul was named the 2010 World Design Capital.