It is possible to observe the use of stone-chamber tombs instead of stone-lined pit burial tombs for Gaya’s upper class in the early 6th century. The early stone-chamber tombs of Gaya are characterized by central passageways and elongated rectangular floors, and are commonly found in the Nam River region. It is also possible to identify stone-chamber tombs built around the same time from Goseong of the southern coastal regions of South Gyeongsang Province. However, these tombs are characterized by rectangular floors, instead of elongated ones.
Distributed around Goseong, stone-chamber tombs with rectangular floors generally have widths of 200cm or greater, with narrow passageways with lengths of 60-80cm. These stone-chamber tombs can be differentiated from stone-chamber tombs with elongated rectangular floors. As the tombs were constructed around the same time as tombs for the highest upper class of Goseong (the Songhak-dong Tombs, Naesan-ri Tombs, and Yeondang-ri Tombs), they became the major stone-chamber tombs of So Gaya.
The possible reason of the emergence of So Gaya stone-chamber tombs may have been the need to place the coffin perpendicular to the corridor near the wall or the possibility of the use of pre-installed wooden coffins. Such burial methods were reflected in the tomb type, resulting in the unique tomb type of So Gaya stone chamber tombs. The So Gaya upper class commonly shared such stone chamber tombs, and this led to the securing of the main ruling power of So Gaya during the early- to mid-6th century. In addition, it was possible to estimate the footholds for regional exchange and relationships with So Gaya through the stone chamber tombs of Jinju, Haman, Uiryeong and Suncheon. This study, which focued on the tomb type featuring a specific structure unique to Gaya during the 6th century used by the upper class of the area, is significant as it views the major area of tomb distribution in political terms.