2,000 runners to tackle Seoul's mountains, streets in 2026 Seoul100K

The 2026 Seoul International Ultra Trail Running Race, also known as Seoul100K, will see 2,000 runners from Korea and abroad tackle Seoul's mountains, fortress walls, riverfront, and downtown streets. The seventh edition of the race will take place over Saturday and Sunday, with three distance categories: 100K, 50K, and 20K. The 100K and 50K races will commence from Gwanghwamun Square at 5 a.m. on Saturday, while the 20K race starts at 7:30 a.m. on Saturday as well.

The races will lead participants through various destinations, including Mount Inwang, Mount Bukhan, the Han River, and Cheonggye Stream. Organizers position the event as an urban trail-running experience that seamlessly blends Seoul's natural landscapes with its historical and modern urban environment. The 100K course allows runners up to 31 hours to complete the challenging route.

Notable international competitors in the 100K race include Petter Engdahl from Sweden, Jasmin Nunige from Switzerland, and Marcel Höche from Germany. Other notable participants include Nora Serres from Norway, Holly Page from Britain, and Stephanie from the United States.