Types and Development of the Late Baekje Pillar-Wall Building Sites

This paper examines the current state and structures of the building sites in Gongju, Buyeo, and Iksan, the central areas of the late Baekje period (Ungjin and Sabi periods) where pillar-wall buildings are primarily found, and defines the individual types of walled buildings. The significant attributes of each building type are derived based on their distribution in each region and statistical analyses, upon which the changes in the form and function of each type of building site are examined. The walled building sites were categorized into three types and an additional special type. In Gongju, they were concentrated in key archaeological sites such as Jeongjisan and Gongsanseong Fortress. The pillar-wall buildings at Jeongjisan and Gongsanseong Fortress, where walls supported superstructures like roofs, were judged to have been clearly planned, displaying hierarchical differences in the layout of the building site. Meanwhile, pit-dwelling structures, created by digging the ground to form the floor and erecting pillars, were still used in areas other than these core sites. Regarding the Buyeo region, at Ssangbuk-ri, located southeast of Busosan Mountain, the earliest features were found to consist of pillar-wall buildings and ground or lifted floor buildings of the post-and-lintel construction style, erected by driving the bottoms of pillars into the ground. In contrast, the Gwanbuk-ri site, situated southwest of Busosan Mountain, seems to have been dominated by foundation stone buildings of the post-and-lintel construction style, erected by using flat and carved stones under pillars erected on the ground. Although this might be due to the spatial arrangement of buildings within the city, it was judged to more likely reflect architectural changes over time. Statistical analysis showed that pillar-wall buildings became increasingly formalized from the Ungjin period to the Sabi period, with the sizes of the first and second types being larger than the third type. In particular, Type 1 pillar-wall buildings were all square-shaped, and there was no significant difference in area from the Ungjin period to the Sabi period, making them the most formalized of all the types of pillar-wall buildings. Also, the area of the (elongated) rectangular pillar-wall buildings in the Gongju region was found to be significantly larger than that of the buildings in the Buyeo region. This difference is believed to be related to the fact that the elongated (rectangular) buildings from the Sabi period were in the form of foundation stone buildings of the post-and-lintel construction style. When examining the changes undergone by each type of pillar-wall building sites, Type 1 showed a tendency for the four protruding columns to gradually move away from the walls, and the oemi-gidoong (i.e. the pillar located in the center of the side wall), which had been clearly present in the early buildings, gradually disappeared. Type 2-1 initially featuring a whole-connected drain but began to deminstrate disconnection, with the doorway becoming more prominent. Type 2-2 was an important building type in the Ungjin period but began to be replaced by foundation stone buildings in the Sabi period, during which its number and size reduced. Type 3 was simple in terms of structure, and evidenced changes in the method of column erection, rather than the plane shape. A-I and A-II were identified from the earliest period, and the A-V types were identified in the latest period. Through a comprehensive review of the distribution and size of the buildings, it is possible to propose that the changes in the nature of the building sites would have proceeded differently for each type, with the Type 1 buildings continuously used as important buildings such as national facilities from the Ungjin period to the Sabi period. It is inferred that the function of the third type changed, and they were used for general residential purposes, except for a few cases.