Expected September 2027
Distance
Climb
Start Time
Cutoff
Terrain
Seoul100K brings trail runners onto the hills around South Korea's capital for three distance options of 20 km, 50 km and 100 km. The flagship 100 km race covers 102.70 km with 4,540 m of climbing and an equal amount of descent, run solo from a 05:00 start. Nine aid stations sit along the route and runners have 31 hours to reach the finish. The event is listed on the ITRA race calendar and carries an ITRA finisher level of 300, with a field capped at 300 runners for the longest distance.
Mountain trails around Seoul
4,540 m of climbing over 102.70 km
9 aid stations across the 100 km route
Terrain
Getting There
Race Day
On the day
Before you enter
Other questions
The 2026 edition takes place on 19 September 2026, with the 100 km race starting at 05:00.
Yes. The 100 km field is capped at 300 participants, so it is worth entering early if that is your distance.
The 100 km course has 4,540 m of elevation gain and 4,540 m of loss, so expect a hilly, sustained mountain route. Prepare for long climbs and long descents rather than a flat run.
ITRA lists a finisher level of 300 for the 100 km, which indicates a demanding mountain ultra. The listed result carries ITRA points toward the ITRA Performance Index.
Entry fee
Registration isn't open yet. We'll show pricing when the organiser confirms.Seoul, South Korea
Expected September 2027
Provisional date, around Sep 18More races like this one
Not open yet
