Incheon, officially the Incheon Metropolitan City (인천광역시), is a city located in northwestern South Korea, bordering Seoul and Gyeonggi to the east. Inhabited since the Neolithic, Incheon was home to just 4,700 people when it became an international port in 1883. Today, about 3 million people live in the city, making it Korea’s third most-populous city after Seoul and Busan. The city's growth has been assured in modern times with the development of its port due to its natural advantages as a coastal city and its proximity to the South Korean capital. It is part of the Seoul Capital Area, along with Seoul itself and Gyeonggi Province, forming the world's fourth largest metropolitan area by population.