Busosanseong Fortress, Buyeo

Busosanseong is the mountain fortress Baekje built to protect its palace when it moved the capital to Sabi, and adults can visit for 2,000 won. It is thought to date from the move to Sabi in 538 or earlier. One trail on Busosan links Samchungsa, Nakhwaam and Goransa, so as you walk you meet the loyalty of Seongchung, Heungsu and Gyebaek, the legend of the 3,000 court ladies and the story of Goransa's spring water. It opens 9:00 to 18:00 from March to October and 9:00 to 17:00 from November to February, every day of the year. The Gwanbuk-ri site below the fortress is thought to be the palace site, and both are part of the UNESCO Baekje Historic Areas.

It was built on the mountain directly behind the Sabi palace, when King Seong moved the capital in 538 or earlier. The Korea Tourism Organization describes it as a mountain fortress combining a ring around the summit of Busosan, south of the Geumgang River, with walls enclosing a valley. In Baekje times it was probably called Sabiseong or Soburiseong, and it was repaired both before and after Baekje fell.

The commentary notes that the river wraps three sides, all but the east, making it a natural stronghold that is hard to see into from outside while giving clear views out. After losing Hanseong to Goguryeo and retreating to Ungjin, Baekje saw this as its last bastion for revival; King Seong completed the fortress before moving to Sabi and renamed the country Nambuyeo.

Toilets and parking are available. For group or discount conditions, ask first on +82-41-830-2880. It closes at 17:00 in winter, so go in early in the afternoon if you plan to walk the whole trail. Other sites in the area are in the Buyeo guide.

Three loyal subjects: Seongchung, Heungsu and Gyebaek; their portraits hang in that order from the left. Seongchung served as Jwapyeong, roughly prime minister, under the last king, Uija. When the king consolidated power through his own faction in 655, Seongchung was imprisoned and, before he died, sent a letter: if the enemy came, stop them at Chimhyeon on land and at Gibeolpo by water. The king ignored it, and four years later the Silla-Tang allied army invaded.

Heungsu, a gifted strategist in distant exile, was asked for advice by letter; he too said not to fight on the plains and to remember Seongchung's words, but others argued an exile would lie out of resentment. After Sabi fell, King Uija regretted ignoring them both. Gyebaek was the general at Hwangsanbeol: the commentary says his 5,000 men won four times against 50,000 Silla troops. When Kim Yu-sin sent the young hwarang Gwanchang alone into the Baekje lines, Gyebaek spared him, but Gwanchang attacked again and was beheaded; the death of the 16-year-old turned the battle, and Gyebaek died fighting.

Nakhwaam is a cliff at the northern end of the fortress that seems to bow its head. Legend says that as Sabi fell, court ladies threw themselves into the Baengmagang River rather than be dishonoured, and their fall was likened to petals, giving the name "rock of falling flowers".

The commentary doubts the number: no record mentions 3,000 court ladies. The phrase first appears in a poem by the mid-Joseon poet Min Je-in, and as it spread, King Uija was distorted into a pleasure-seeking king. In fact he was so filial as a boy that he was called the Zengzi of the East, and he took more than 30 fortresses from Silla. The commentary ends by saying the sorrow of Nakhwaam belongs not only to the court ladies but to the soldiers and people driven here.

A mountain spirit told a childless old couple in Sobu-ri that the water from a crack in the rocks by the river would make them young. The old man kept drinking it until he became a baby; his wife raised him, and he later became a Baekje Jwapyeong. King Uija is also said to have loved the water; because it was far from the palace, he had a goran fern floated on it to prove it was genuine, and he stayed vigorous and free of stomach trouble. The spring is behind Goransa.

• In winter it closes at 17:00, so enter early if you plan to walk to Nakhwaam and Goransa.
• Bring proof if you qualify for free entry.
• Wear comfortable shoes for the mountain trail.
• At Samchungsa, the portraits are Seongchung, Heungsu and Gyebaek from the left.

The Gwanbuk-ri site, around 725 Gwanbuk-ri below the fortress, yielded roads, drainage and pottery and is now thought to be the palace site, suggesting the palace and fortress were joined. Busosan also holds Nakhwaam, Baekhwajeong, Sajaru, Banwollu, Gungnyeosa, Goransa, Yeongillu, the Gunchangji granary site and the pit barracks site. A Sabi capital virtual experience hall recreates the site, and the Daebaekje festival is held every autumn. Nearby are the Jeongnimsa Temple Site pagoda, the Gua-ri site, the Ssangbuk-ri kiln site, Buyeo Hyanggyo, Gungnamji and the Buyeo National Museum; see Gungnamji and Jeongnimsaji to piece together the Sabi capital.

Fees, hours and programmes can change, so check the latest information before you visit.