Gongsanseong Fortress

Gongsanseong is the mountain fortress that guarded the royal capital of Baekje while it was based at Ungjin, today's Gongju, from 475 to 538. Its walls run for about 2.66 km along a ridge about 110 m high south of the Geumgang River, and from the ramparts you look out over the river and the town. In 2015 it was inscribed with the Songsan-ri tombs and other sites as part of the UNESCO World Heritage Site "Baekje Historic Areas".

History: Baekje's second capital

After losing its capital Hanseong to Goguryeo, Baekje moved to Ungjin under King Munju in 475, and it remained the centre of the kingdom until King Seong moved the capital to Sabi (Buyeo) in 538. The fortress was first built of earth, and most of it was rebuilt in stone during the Joseon period. Today about 1,925 m of stone wall and 735 m of earthen wall survive.

Right after Baekje fell, King Uija stayed here briefly, and the fortress became a base for the movement to restore the kingdom. In 822, under Unified Silla, Kim Heon-chang's rebellion broke out here. During Yi Gwal's rebellion in the Joseon period, King Injo fled to Gongju and waited at the site of Ssangsujeong, the highest point of the fortress, for news that the revolt had been put down. Afterwards the fortress was also called Ssangsu Sanseong. Its name changed with the times: Ungjinseong under Baekje and Gongsanseong under Goryeo.

What to see

• Geumseoru: The west gate pavilion, restored in 1993 together with Yeongdongnu, the east gate. The group of steles stands by this entrance.
• Gongbukru and Jinnamnu: The north and south gate pavilions survive from earlier times. The Geumgang flows right past Gongbukru.
• Manharu and Yeonji Pond: A pavilion and a stepped stone pond below the wall on the river side.
• Presumed royal palace site and Ssangsujeong: Excavations revealed what is thought to be the Baekje palace site, along with ponds.
• Steles: At the Geumseoru entrance, 47 steles, mostly honouring local officials, have been gathered from around Gongju.
• Yeongeunsa: A temple inside the walls where monk-soldiers trained during the Japanese invasions of the 1590s.

The name and the excavations

There are two stories about the name Gongsan. One says that from across the river the hill looks like the Chinese character gong, meaning a noble person, but many see this as an explanation invented after the name was written in characters. Just as Ungjin, Gongju's old name, meant "bear ferry", Gongsan may originally have been "Gomsan", bear mountain. After King Injo's stay it was also called Ssangsu Sanseong.

The fortress is an elongated shape about 800 m east to west and 400 m north to south. Baekje roof tiles, including lotus-patterned end tiles, pottery and many Goryeo and Joseon objects have been found inside, and excavations since the 1980s revealed how the walls were built and the remains of palace buildings. Hidden gates, bastions, a command post and a water gate also survive, so it is a good place to understand how a Korean mountain fortress works. Gongsanseong is also listed among the Ten Views of Gongju.

Tripto tips

• Opening: 09:00–18:00 from March to October and 09:00–17:00 from November to February, with last entry 30 minutes before closing. Closed on 1 January, Seollal and Chuseok.
• Tickets: KRW 3,000 for adults, KRW 2,000 for teenagers and KRW 1,000 for children. Parking is free.
• Time: About 2 hours to walk the full circuit of the walls. There are ups and downs, so wear comfortable shoes.
• Night views: The walls are lit up after dark.
• Combine with: The royal tombs of Gongju (Songsan-ri tombs), home to King Muryeong's tomb, are close by.