Japan requires the giteki mark. For a short trip, rent a digital simple radio (RadiGo from ¥4,000 for 2 days; the renter does not register), or buy two 10 mW specified low-power radios locally (about ¥5,000–10,000 each). Korea requires a KC-certified digital personal radio (424/448 MHz, 0.5 W), about 4,400 won a day to rent; analog units stop being legal after 2026. For SOS: bring your inReach to both; a PLB may not be activated on land in Japan and is not permitted in Korea; iPhone satellite SOS works in Japan but not in Korea.
Read a finger crack by how deep your fingers go: only to the first knuckle is tips, to the second knuckle or the base of the fingers is a good finger crack, and in but wobbling is rattly fingers. For the good size, go thumb down: fingers in to the base, palm and forearm flat on the rock, rotate the elbow down until the forearm lines up with the crack, and pull down, not out. Too thin, flip to pinkie down; rattly, rely on torque and push your thumb on the edge; any wider is off-fingers. Knuckles locked above a constriction cost the least effort, and pin scars are ready-made constrictions, though they are hard to protect and hard on your toes. Feet go on face holds first, then toe jams or front-on smears on the crack edges. If the jam won't stick, the edge is good to grip and the wall isn't steep, layback. A millimeter changes everything, so measure cracks with your own fingers.
In a hand crack a foot jam takes four steps: drop the knee outward so the foot turns to its thinnest side (little toe down), slide the toes in, then bring the knee back in line with the crack so the foot twists tight. The most common mistake is getting only the tips of the toes in. Sources disagree on depth; Pete Whittaker's sweet spot puts the crack edge half to a full toe's length past the webbing of your toes. As you weight it, let the heel sit lower than the toes: pressure moves off the toe knuckles and the jam gets more secure. Foot pain usually means over-twisting or shoes that are too tight. To get out, reverse it: knee out, ankle relaxed. Finger cracks take only the toe; fist cracks take the whole foot straight in.
Before you climb a crack, work out how wide it is: tips, fingers, off-fingers, hands, fists, offwidth, squeeze or chimney. Each size has its own jams. But you measure the size with your own hand. Pete Whittaker's comparison: cam sizes 0.75 and 1 are perfect hand jams for small hands and thin, strenuous jams for big ones; a #4 is a fist jam for big hands and a butterfly stack for small ones. So 'this one's easy' from a friend may not apply to you, and you have to climb every size for the difficulty to even out. The series starts with hand cracks, the easiest to learn, and works outward toward narrower (fingers) and wider (fists, offwidths), with 2020-or-later videos from many crags and climbers in every post.
A hand jam's strength comes from the thumb, not the fingers: relax and flatten the hand, slide it in to the wrist, then tuck the thumb into the palm and push it toward the little finger so the muscle at its base presses on the rock. The fingers only help. The most common mistakes are not going deep enough, grabbing the crack edge with your fingers, and jamming at chest height. Thumbs up to move up, thumbs down to rest or place gear; cross hands in straight cracks, shuffle in leaning cracks and corners. A crack that's perfect for big hands may be cupped hands for small ones, so find your own 'hand number' first.
Where 20 Insubong routes start, how long each pitch is, which pitch is the crux and how to get down, including Insu A, Insu B, Lonely Road, Chouinard A/B, Biwon, Yangji, Crony and Dongyang, compiled from Korean climbing-community write-ups dated 2006 to 2024. This is not a topo: there are no wall photos or route numbers, so carry the Mont Blanc Lines East Face topo on the day; the page also lists where to find the Korean community's topo drawings.
Ganhyeon combines easier slabs, face routes and 5.12–5.13 cave climbing with a relatively straightforward approach. Consider cool sunny days, check that its limited 5.11 selection suits you, and walk in from designated parking.
Gochang’s Halmae-bawi offers vertical to gently overhanging pocketed sport climbing, an alternative to steeper Seonunsan sectors. Confirm the Gochang location, current access across local land and the Korean route names before travelling.
Insubong offers granite cracks, friction slabs and chimneys in Bukhansan National Park. Insu A and Chouinard B are graded YDS 5.8, but still require trad, multipitch and descent skills. Take the Ui–Sinseol Line to Bukhansan Ui Station, then a taxi to the Baegundae trailhead to save the uphill road walk.
Janggunbong in Seoraksan has Front and Southwest Walls with granite cracks, slabs and face climbing. A2O and the Standard Route offer different grades and lengths. Choose the face and full route before arranging park authorization.
Jeokbyeok is a west-facing granite wall beside Biseondae, with steep cracks and overhangs. Solo is listed as 5.8/A1, Echo as 5.11c/A2 and Mura as 5.9/A4: the free grade alone is not a route-selection guide.
Munsusan offers upper and lower south-facing gneiss crags near Ulsan. Sunshine makes it a winter option but a warm-weather drawback. Choose your sector and route length before planning the observatory parking approach and return transport.
Seoninbong is a granite wall in Dobongsan with cracks, slabs and multipitch climbing; Leopard (표범길), Bat (박쥐길) and Yodel Buttress are the recognised classics. Even the moderate lines need your own protection, and most teams climb to mid-height and rappel the route. Subway lines 1 and 7 run to Dobongsan Station, about 40 minutes' walk from the wall; the closure after the 2025 rockfall was lifted that May, but check the KNPS live notices before you go.
Seonunsan brings vertical faces, pockets and steep sport routes into neighbouring sectors. Soksal and Tugu offer demanding climbing, while Mun includes easier routes. Choose the sector for your grade and sunshine, and treat temple-side access separately.
Ulsanbawi in Seoraksan offers granite cracks, chimneys and multipitch routes. The complete ridge is a different, multiday objective. Choose the wall route or ridge first, then confirm park authorization and the approach.
Yuseondae combines ridge climbing and southwest-facing granite multipitch. MP lists Longing for Two as 5.8 and 11 pitches, and Yoosun AB as 5.10b and six pitches. Choose the style before planning the approach and descent.