excavations of the Bokcheon-dong burial mounds in the Port of Busan uncovered grave goods that suggest a powerful and complex chiefdom inhabited the area when the Three Kingdoms of Korea were forming from the 2nd to the 4th Centuries AD.
Archaeologists found over 250 iron weapons and ingots in a wooden chamber tomb in today's Port of Busan. Called Geochilsan-guk (meaning "rough mountain"), the town was absorbed by nearby Silla and renamed Geochilsan-gun. The town was renamed Dongnae in 757.