As the early iron age drew to a close, a new type of iron culture emerged in the Bukhan River basin, centered on the Daeseong-ri and Daljeon-ri sites in Gapyeong and the recently excavated Geumnam-ri in Namyangju. This is a combination of a new forged iron culture centered on “forged weapons” and the cast iron culture of the early iron age represented by rectangular cast iron parts and cast iron forges. This iron culture has long been regarded as a transplantation of the advanced Han iron culture after the establishment of the Lelang Commandery. However, this new type of iron culture does not introduce typical Han ironwork. In other words, the iron culture that appeared in the Bukhan River basin was based on the Gojoseon iron culture, which centered on cast iron. Moreover, it was the combination of forging technology introduced in Northeast Asia around the time of the Qin-Han dynasty that coincided with the transition to
 forged iron. Based on these characteristics, it is more reasonable to assume that the power that was able to form the new iron culture was Wiman Joseon, which was able to acquire Han military wealth in addition to the Gojoseon tradition. It is believed that the new iron culture established by Wiman Joseon first reached the southern part of the Korean Peninsula, especially the Bukhan River basin. This was because these local forces were either the most external forces directly influenced by Wiman Joseon or were closely involved in Wiman Joseon's ironware distribution network. In other words, the close influence from the "center" was the first factor that led to the development of a more advanced iron culture in the southern part of the Korean Peninsula that was different
 from the early iron culture of the previous period. However, this geopolitical proximity to the “center” may have paradoxically contributed to the lack of succession of the introduced iron culture within the community. Political and economic stimuli from outside, such as the establishment of the Lelang Commandery, contributed to the absence of iron and other archaeological elements in the Bukhan River basin for a considerable period of time. This is evidenced by the disappearance of most archaeological elements, including iron, in the period between the fall of the Wiman Joseon Dynasty and the establishment of the Lelang Commandery.