The ancient tombs excavated in Daho-ri, Changwon in Gyeongsangnam-do Province are classified as early wooden coffin burials, providing new information on the formation of ancient kingdoms in Korea. The most distinctive feature of the Daho-ri wooden coffin tombs is a pit called a yogaeng (腰坑, literally, “waist-pit”) made underneath the coffin in the center bottom of each tomb. Such type of a pit was first discovered in Daho-ri tombs. Inside the pit was a basket packed with multiple relics, including weapons such as Korean-type bronze daggers with lacquered sheaths, iron swords, bronze and iron socketed spearheads, and arrows; iron agricultural tools, including wooden hand plows and axes; personal accessories such as Chinese mirrors, belt hooks, and beads; wooden lacquerware; fans; horse bells; wuzhu coins; and brushes. The excavation of Chinese mirrors and wuzhu coins indicates that the Daho-ri tombs were built during the late first century BCE. According to historical records, the Byeonhan Confederacy controlled a number of iron mines, possessed considerable iron manufacturing technology, and supplied iron to Nangnang and Japan. They also used iron as currency. At the time, the Byeonhan ruling class accumulated wealth by producing, controlling, and trading in iron, which allowed its members to sustain and expand their power. The ancient tombs in Daho-ri belonged to such members of the ruling class of Byeonhan society. The occupant of Tomb No. 1, in which the most diverse and greatest number of relics were found, appears to have been a ruler of Byeonhan.