Gyeryongsan became a national park on the last day of 1968, the second in Korea after Jirisan. It is a compact granite massif an hour south of Seoul by train and bus, ringed by three old temples, and it has one peculiarity that shapes every walk on it: you cannot go to the top.
The summit is a legal no-entry zone
Cheonhwangbong stands at 847 m and no course goes there. It is not a designated trail, and under Article 28 of the Natural Parks Act that makes walking on it an offence punishable by a fine of up to 500,000 won. The park is explicit about why: sections outside the trail network have no railings and no steps, which makes them dangerous, and traffic on them damages the ground and raises the fire risk.
It is worth being precise about the reason, because it is easy to assume otherwise. There is no military installation on Cheonhwangbong in anything the park publishes. The closure is an ordinary designation under the Natural Parks Act, the same instrument that governs off-trail walking anywhere in the Korean park system. What you get instead of the summit is Gwaneumbong at 766 m, and in practice that is the peak the mountain is climbed for.
The ridge the park tells you to think twice about
Between Gwaneumbong and Sambulbong runs a kilometre of bare granite called Jayeonseongneung, the natural fortress ridge, so named because it looks like a city wall. Korean park descriptions are usually measured. This one is not.
That last clause is rare. Korean national park text will tell you a section is difficult; it does not often tell you to skip it. Three of the courses here cross the ridge in full - the Donghaksa circuit and both temple-to-temple traverses - and if you want the mountain without it, the short climb to Gwaneumbong turns round before it starts. There is also a marked bypass around the steep climb onto Sambulbong at the northern end.
Four valleys, and they do not run to the same clock
Donghaksa on the east, Gapsa on the west, Sinwonsa to the south and Sutonggol away in Daejeon. The first three are in Gongju and share a timetable. Sutonggol is a different city, a different valley and an hour later at the gate.
The practical consequence: the 11.8 km circuit takes six hours, so a winter start after about 08:30 leaves you finishing in the dark, and a start after 15:00 will not get you through the gate at all.
Read the word "one way" carefully
Four of the nine courses carry the Korean word for one way in their names, and the park uses it in two different senses. On the short courses it means the climb only, stopping at a peak - Donghaksa to Gwaneumbong, Gapsa to Sambulbong, Sutonggol to Geumsubong. The published distance and time cover going up and nothing else, so budget for the descent yourself rather than assuming the figure is a round trip.
On the long traverses it means a single direction across the mountain, which is a different thing again. And on one course the word is simply wrong: the Donghaksa circuit is described as 11.8 km one way when its own description starts and ends at the same car park. Take that at face value and you would arrange a pick-up you do not need, or worse, leave a car where you are never going to arrive.
The fire season barely touches this mountain
Mountains elsewhere in Korea lose whole ridgelines for two months every spring. Gyeryongsan does not, and the contrast is instructive about how the system works.
The closed link is the connection between the Donghaksa valley and Sutonggol. It is not part of any of the nine numbered courses, although the Sutonggol circuit does pass over Jatigogae at one end of it. As of late September 2026 the park had not posted an autumn notice, so treat the dates above as the pattern rather than a promise.
What the temples add
Three old foundations sit at three of the four trailheads, and they are part of the reason people walk here rather than somewhere steeper. Donghaksa runs a monastic college. Gapsa holds a hanging scroll painting listed as a national treasure. Sinwonsa has one of its own, and beside it Jungaktan, a site used for state ritual.
The park also frames the walking around a set of named scenes, the eight views of Gyeryong, which it lists piecemeal across the course descriptions rather than in one place: the autumn maples of the Gapsa valley, mist at Eunseon Falls, sunset from Yeoncheonbong, cloud on Gwaneumbong, snow blossom on Sambulbong, moonlight on the Nammaetap pagodas, new green at Donghaksa. That is seven of the eight. The park does not say anywhere what the eighth is.
One naming note, since the mountain has lent its name to a city: Gyeryong on its own may mean Gyeryong City, the municipality at the southern foot, rather than the mountain. The park says the name came from a fourteenth-century reading of the landscape as a golden fowl brooding an egg and a dragon rising to heaven, and that the two creatures gave the mountain its two syllables.
What the park does not publish
No cumulative climb figure exists for any course here, so the route cards carry distance and time only. Trailhead elevations are not published either, which means the height gained cannot be worked out from the official numbers.
Two of the park’s own figures contradict each other. Yeoncheonbong is given as 738.7 m on one course page and 743 m on another, in what is otherwise the same sentence copied across, so there is no height to quote for it. And the short Sinwonsa climb to Yeoncheonbong carries a published time of 4 hours 50 minutes against 1 hour 50 minutes in its own text and in the neighbouring course that shares the section - a three-hour spread with nothing to settle it. For that climb, take the Sinwonsa traverse above, which covers the same ground.
Nor could we establish from any official source whether the three temples charge a cultural property fee. The park fee page is silent on it and one course description still refers to a ticket office at Donghaksa. Rather than quote a number we cannot stand behind, we have left the fee line blank.