乐浪郡
The Korean iron age began around the 5th to 4th century BC with the arrival of the Chinese iron culture; it most likely began through the contacts with the North-East Chinese state of Yan and was later developed through the Chinese Lelang Commandery. Koreans have always tried to import Chinese technology and reshaped it in their own in order to make it uniquely Korean and in order to develop new technology. The introduction of Chinese iron culture contributed to the rapid development of ancient Korea. The Koreans then localized the Chinese iron culture into a new form of Korean iron casting technology. By 300 BC, iron was widely used in Korea; however, the Iron culture of Korea continued to be deeply influenced by China which is attested by numerous archeological artifacts. Korean pottery advanced with the introduction of the potters wheel and climbing kiln firing.