Samnyeonsanseong
Silla-era mountain fortress pivotal in Korean unification.
Samnyeonsanseong (Korean: 삼년산성; lit. 'three-year mountain fortress'), also called Samnyeon Sanseong Fortress, is the remains of a stone-walled Korean fortress in Boeun County, North Chungcheong Province, South Korea. Construction began in 470, during the Silla period, and the fortress was rebuilt in 486. It was designated Historic Site of South Korea No. 235 on May 25, 1973, and has been placed on South Korea’s tentative list for UNESCO World Heritage status.
The fortress walls originally stretched 1,880 meters, built with alternating rows of slim, flat stones laid horizontally and vertically, creating a strong structure. The walls, set on vertical cliffs, reached 13 to 20 meters in height and 5 to 8 meters in width, incorporating earthen ramparts. Features include four gates spaced roughly equally (each about 4.5 meters long), seven curved guard bastions (ongseong) placed at vulnerable points (25 meters in circumference, 8.3 meters high), two sluice gates, and five wells. A large pond once sat inside the fortress, serving as a key water source, though only its outline remains.
The fortress follows the Teimeui style of Korean mountain fortress, with walls built around mountain peaks like a folding screen. It occupied a strategic location and is credited with aiding Silla’s unification of Korea. In the late seventh century, Silla used it as a base to attack Baekje to the west and prepare advances against Goguryeo to the north, helping secure the Han River Valley and central Korean peninsula. Its reputation is such that Wanggeon, first king of Goryeo, reportedly failed to capture it in 918. Excavations in 1983 uncovered artifacts from the Three Kingdoms period through the Joseon dynasty, indicating periods of occupation. Thousands of tombs surround the fortress, and engraved calligraphy on a boulder at the entrance has been attributed to Kim Saeng.
The name’s origin is debated. The Samguk Sagi records that the fortress was completed in three years (Korean: sam nyeon), giving it the name, and that the nearby town (then known as Samnyeon-gun or Samnyeonsan-gun) derived its name from the fortress. However, some believe the fortress was named after the town. The Veritable Records of the Joseon Dynasty show it was also called Ojeongsanseong (오정산성; 烏頂山城) during the Joseon dynasty, after its location on Mount Ojeongsan.
Quick Facts
- Location
- Boeun County, South Korea
- Built
- 470
Facts from the source article.
Lore & Background
The fortress was built in 470 and reconstructed in 486. During the Three Kingdoms period, the town of Boeun-eup, located two kilometers from the fortress, was known as Samnyeon-gun or Samnyeonsan-gun, and it is believed by some that the fortress gets its name from the town. However, the Samguk Sagi relates that the fortress was completed in three years (Korean, sam nyeon), and that the fortress derived its name from this fact, suggesting the nearby town derived its name from the fortress instead. The Veritable Records of the Joseon Dynasty show that the fortress was known as Ojeongsanseong (오정산성; 烏頂山城) and was used during the Joseon dynasty, a name derived from its location atop Ojeongsan Mountain.
Reader's Guide
Samnyeonsanseong is valuable for demonstrating building techniques employed by the Silla during the late fifth century. Its walls, built by alternating rows of slim and flat stones in horizontal and vertical layers, resulted in a very strong structure. The fortress exhibits characteristics typical of a Korean mountain fortress, specifically the Teimeui style, where walls are built around the peaks of the mountain like a folding screen. It occupied and protected a strategic location, credited with helping Silla achieve the unification of Korea. During the late seventh century, Silla used the fortress as a base to attack Baekje to the west while preparing for advances against Goguryeo to the north, and it was pivotal in securing the Han River Valley. The fortress's reputation is such that it is said Wanggeon, the first king of Goryeo, failed in his attempt to take it in 918. Excavations in 1983 of artifacts from the Three Kingdoms period up to the Joseon dynasty give clues to its occupation and use. Thousands of tombs surround the fortress, and engraved calligraphy on a boulder at its entrance has been attributed to Kim Saeng.
Did You Know?
- The fortress was built beginning in 470 and reconstructed in 486.
- Its walls measured 1,880 meters in length and ranged from 13 to 20 meters in height.
- The fortress is said to have been unsuccessfully attacked by Wanggeon, first king of Goryeo, in 918.
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