Insubong is the main attraction for climbers in Bukhansan National Park, and one of the best in all Korea. Perhaps only Seoraksan National Park has as big, varied, and numerous routes. There are over 80 routes on the mountain, route maps will be uploaded as images. As generalism, Koreans underestimate their grades, and so this can present a very challenging mountain indeed. Despite the difficulty, it can get very crowded. The Koreans commonly work in large groups expedition style on this mountain. You may find groups of up to 10, or more making their way up a single route, with dozens of these groups every day in peak season. Generally the leader of the group will be a very solid climber, but will set ropes and the rest of the group will use ascenders or other aid climbing equipment to follow. Often they groups will leave fixed ropes on the route to faciliate rappells at the end of the day. Do not be surprised to see many ropes tied into a single anchor to climb or even rappel at the same time. For a more 'alpine' experience, go during weekdays, and regardless of the day, try and get at the mountain by 7am at the latest. The first subways/buses of the day around 530-600am are a must. If you have a car, I'd suggest going even earlier, perhaps arriving at 600am to the park.
The Koreans are installing fresh bolts in 2016, but unless your route is 100% slab and bolts, its good to bring at least a small rack of cams from .3-2. Koreans tend to space out bolts further than in USA, so it may be more comforting to be able to place some pro in-between.
See the parent page, Bukhansan National Park, for how to get to the general area.
From the Do-Son-Sa parking lot follow the main trail up towards Baekundae. Just before getting to the ranger station, go off the main trail to the right, across some large boulders, and find the smaller climbers trail on the far side of that draw. Follow this climbers trail up towards Insubong. This trail will take you generally to the base of the great slab on the southeast corner of the mountain. From there, trace the bottom of the rock face around the mountain to the start of your selected route.
Many climbs are slab and/or aid, and are bolted. However, there are some fantastic cracks on the mountain that will satisfy trad/alpine climbers. Below are listed some of the "classic" routes on the mountain:
Chuinard A: A physical hand/offwidth crack that goes on for 4 pitches. Rated 5.10a, and quite difficult indeed.
Chuinard B: A less difficult broken crack system further south along the face from Chuinard A. Rated at 5.8; 6 pitches.
Insu A: A crack/chimney system that follows the gully south of Chuinard B. Rated at 5.8, 4 pitches
Insu B: A combination of face/slab, crack, and chiney that is more toward the southwest of the mountain, 5.8; 6 pitches.
Geodeok Way Gil: A series of cracks and slabs that comprises the northeaster ridge up the mountain. Possibly the easiest way to the top, 8 pitches of 5.6.
Simu: A combination of face, cracks, chimneys, and some aid located to the climbers right of Chuinard A. 5.9/A0 but climbs hard for its rating.
Insu Ridge: On the north side of the mountain this long route can be done with mostly scrambling but there are sections requiring technical climbing up to 5.8/A0.
All routes that make it to the summit can use the primary abseil point, which is located on the southwest side of the mountain, above the saddle high-point between Insubong and Baekundae. This rappel can only be done with 2x60m or longer ropes. There is one intermediate anchor on this rappel site, however it is at the very end of a 2x50m abseil, so it is safest/most efficient to use 2x60m ropes and not chance it. Other than this, you can always rappel back down the way you came up, but even then, some routes will not work with a single 60m rope.
See the parent page for red tape, camping, seasonal information.