Gongsanseong: The Capital Baekje Built After Losing One

There are two reasons a kingdom moves its capital. It found somewhere better, or it lost where it was.

Gongsanseong is the second. Baekje lost its capital on the Han River, came south, and settled on this low hill beside the Geum. That circumstance is still legible in the shape of the fortress, which makes this the place to start if you want to understand not what kind of kingdom Baekje was, but what kind of position it was in.

Opening hours and location are on the place page for Gongsanseong. This article is about what the fortress was for, and why it went on being used long after the court left. For where Baekje sat among its neighbours, see the Three Kingdoms.

At a glance

A capital until 538
It was Baekje's walled capital until the court moved to Buyeo in 538, and under Baekje it was called Ungjinseong.
Earth, then stone
It began as an earthen rampart and was rebuilt in stone under Joseon.
Two of the four gates are rebuilds
The south gate Jinnamnu and north gate Gongbungnu survived; Yeongdongnu and Geumseoru were rebuilt on the east and west gate sites in 1993.
World Heritage since 2015
One of the eight components of the Baekje Historic Areas.

The year 538

It helps to start with one number.

Gongsanseong was Baekje's walled capital until the court moved to Buyeo in 538, the sixteenth year of King Seong. Against a dynasty that lasted close to seven centuries, the stay at Ungjin was a short one, and the shortness is the character of the place.

Baekje did not intend to stay. It took a defensible hill, caught its breath, and moved back out to open ground. The next site was Busosanseong.

So the things the phrase "Baekje's capital" leads you to expect — a broad plain, a grid, a large palace platform — are not here. There are valleys, ridges and a river instead.

A fortress with its back to the water

The north gate is Gongbungnu. Step out of it and you crossed the Geum River by ferry.

One gate explains the whole logic. This is not a fortress that puts a river in front of it to stop an enemy; it is a fortress that puts a river behind it to keep a way out. Having a way out means the rear is open, and an open rear means this was never meant to be the last line.

The plan is roughly rectangular, about 800 metres east to west and 400 north to south. That is a walkable circuit, and walking it takes you up and down as the wall follows the valleys. It does not simply ring a ridge; it wraps valleys inside itself, which brings water and level ground within the walls.

Two periods in one wall

The wall you walk is not from one century.

It was originally an earthen rampart and was rebuilt in stone under Joseon. So "walking Baekje's wall" is half true. The line is Baekje's; the stone is not.

With old built structures in Korea this is the rule rather than the exception. Timber buildings are repaired and re-raised as a matter of course, and a collapsed stretch of rampart is rebuilt with whatever technique the age has. What survives is not the material but the position.

The names stack up the same way. It was Ungjinseong under Baekje, Gongjusanseong and Gongsanseong under Goryeo, and Ssangsusanseong from King Injo's reign onward. One hill, three names, each naming what the age used it for.

The longer half of the story comes after the capital leaves

The fortress kept working after Baekje moved to Buyeo. The list is long and mostly not good news.

King Uija stayed here briefly immediately after Baekje fell, and it then became a base of the Baekje restoration movement. That a king went to the old capital's fortress the moment the kingdom collapsed says it was still read as somewhere you could hold out.

Kim Heon-chang's revolt broke out here in 822 under Unified Silla, and King Injo fled here during Yi Gwal's revolt in 1623. Two events more than eight hundred years apart, on the same hill.

Which means the real record of Gongsanseong is not "Baekje's capital" but "the hill people went up when something went wrong". The years as a capital are only the first entry in a much longer list.

The gate in the photographs is from 1993

One thing worth knowing before you look at the real thing.

Gate sites were identified on all four sides. The south gate Jinnamnu and the north gate Gongbungnu were still standing; the east and west survived only as foundations, and in 1993 Yeongdongnu was rebuilt on the east site and Geumseoru on the west.

The tiled gate pavilion you see first from the entrance is Geumseoru. That it dates from 1993 is not a disappointment but a thing to read: what survived and what was rebuilt stand in the same fortress, and once you know which is which the age of the wall becomes visible.

The site was designated a Historic Site on 21 January 1963 and covers 376,645.3 square metres.

Walk down to Gongbungnu. The logic of the fortress is clearest there — the river begins just outside the gate, and beyond it is the north Baekje had left behind. You can get up onto the wall almost anywhere, but the gate that answers "why here" is the one facing north.

Worth pairing with this

Frequently asked questions

How long was Gongsanseong the capital of Baekje?

Until the court moved to Buyeo in 538, the sixteenth year of King Seong. Under Baekje the fortress was called Ungjinseong.

Is the wall I am walking on Baekje's?

The line is; the stone is not. It was originally an earthen rampart and was rebuilt in stone under Joseon.

Is the gate at the entrance original?

Geumseoru on the west gate site and Yeongdongnu on the east were rebuilt in 1993. The gates that survived are the south gate Jinnamnu and the north gate Gongbungnu.

Was it used after Baekje fell?

Yes. King Uija stayed here immediately after the fall and it became a base of the restoration movement; it was used again during Kim Heon-chang's revolt in 822 and Yi Gwal's revolt in 1623, when King Injo fled here.

Why is it World Heritage?

It is one of the eight components of the Baekje Historic Areas, inscribed in 2015. UNESCO describes the property as eight archaeological sites dating from 475 to 660 CE and groups Gongsanseong with the Songsan-ri royal tombs under the capital Ungjin.