Runners start · local time — 100M Fri 21:00 / 100K Sat 05:00 / 60K Sat 08:00 / 20K Sat 10:00 (based on the 2026 edition)
Trans Jeju is a course built around the concept of climbing "from zero to the summit" of Hallasan.
The 100K (104km, more than 4,000m of elevation gain), which draws the most runners, starts at 05:00 from Jeju World Cup Stadium in Seogwipo.
A reporter who finished the 2025 edition described this course as "a structure that climbs Hallasan twice,
loops the trail and returns to the start." The organizers describe Hallasan National Park as a UNESCO World Natural Heritage site,
with more than 1,800 plant species growing across its elevations and the world's largest Korean fir forest around the summit.
The Yeongsil rock cliffs and the Baengnokdam crater lake are also part of the course.
But the terrain is too tricky to take on for the scenery alone.
The 2025 edition saw rain all day, and runner after runner reported struggling on wet rock and mud;
835 of the 937 starters in the 100K finished (2025 figures).
The race is organized by A-Plan, and 100K finishers receive 3 UTMB Running Stones, which count toward the UTMB Finals draw.
The 100M is 148km with more than 5,000m of elevation gain and a 37-hour time limit, and the organizers present it as the hardest event.
Participation grows every year: local media reported that about 5,300 runners from 53 countries are expected in 2026 (based on the 2026 edition).
