Yamato period
Polities were situated in the alluvial flats of tributary river valleys and the mouth of the Nakdong. In particular, the mouth of the Nakdong has fertile plains, direct access to the sea, and rich iron deposits. Gaya polities had economies that were based on agriculture, fishing, casting, and long-distance trade. They were particularly known for its iron-working, as Byeonhan had been before it. Gaya polities exported abundant quantities of iron ore, iron armor, and other weaponry to Baekje and the Kingdom of Wa in Yamato period Japan. In contrast to the largely commercial and non-political ties of Byeonhan, Gaya polities seem to have attempted to maintain strong political ties with those kingdoms as well.