Multi-story Multi-angular Building Site of Baekje Discovered at Sejong Iseong (李城)

Panoramic view of the Baekje period 'multi-layered multi-sided' building site discovered in Sejong Iseong. Provided by Sejong City

[Asia Economy (Sejong) Reporter Jeong Il-woong] At ‘Iseong (李城)’, Monument No. 4 in Sejong City, the remains of a multi-sided, multi-storied building from the Baekje period have been discovered. This is particularly significant as it is the first case nationwide where a Baekje multi-sided, multi-storied building site has been found preserved in its original form.

Sejong City announced on the 23rd that during the excavation survey of Sejong Iseong, conducted in collaboration with the Hanseong Cultural Heritage Research Institute, they confirmed the remains of a multi-sided, multi-storied building constructed in the 7th century Baekje period.

After conducting a trial excavation of Iseong last year, the city and the research institute have been excavating the flat area composed of four terraced levels within the fortress and the surrounding eastern wall section since June.

The multi-sided, multi-storied building site discovered during the excavation is estimated to have been built during the Sabi period of Baekje on the first terrace of the terraced flat area, and it has been confirmed that the building site is very well preserved.

The structure on the first terrace consists of 12 square-shaped foundation stones placed centrally, with additional foundation stones arranged in three rows?inner, middle, and outer?at 30-degree intervals around the perimeter, completing a 12-sided polygon. Additionally, the floor at the center of the square shape has grooves carved in a cross (十) pattern.

Based on this arrangement of foundation stones, the city and the research institute estimate that the building erected on the site was a multi-storied structure with two or more floors, where the first floor was dodecagonal (12-sided), and the upper floors had a rectangular shape.

Until now, there have been no known cases in Korea of a 12-sided multi-storied building site being discovered. The city emphasizes that the multi-sided, multi-storied building site found at Iseong is the first case with a relatively perfect original form.

The construction period of the building is estimated to be the 7th century Sabi period of Baekje, based on artifacts excavated nearby, raising expectations that this will be an important resource for understanding and restoring Baekje culture in the future.

In addition, on the second and fourth terraces of the terraced flat area, square-shaped foundation stone building sites were confirmed, and on the third terrace, a clay water storage facility was found.

This suggests spatial differentiation according to the hierarchy within the fortress, increasing the possibility that Iseong was used as a space for national ceremonial activities.

Moreover, on the eastern wall, traces were found of a drainage wall inside the stone fortress wall constructed with an inner and outer layer?a first among ancient Korean mountain fortresses?along with an internal water collection facility.

The city explains that this is a facility for managing water flow inside the fortress, representing an advanced drainage technique equipped with two water outlets passing through the fortress wall and an external stone water facility.

Meanwhile, Iseong, located in Songsan-ri, Jeonui-myeon, Sejong, is understood to have been initially constructed during the Baekje Sabi period and partially repaired during the Unified Silla and Goryeo periods.

Notably, artifacts such as the Kaewon Tongbo (開元通寶) coins, numerous roof tiles found at each terrace’s building sites, and lotus-patterned ridge-end tiles discovered at the square-shaped building site indicate the former prestige of Iseong.

Lee Hyun-gu, head of the Tourism and Cultural Heritage Division of the city, said, “Sejong Iseong has long been recognized as a valuable resource to reveal the characteristics and historicity of mountain fortresses from the Three Kingdoms period. The city plans to confirm Iseong’s historical value through annual excavation surveys and restore and maintain it to create a historical education site accessible to citizens.”