Trans-Jeju is a coast-to-coast mountain crossing of Jeju Island, connecting the southern city of Seogwipo with Jeju City in the north while passing over the summit of Hallasan, the highest mountain in South Korea.
The route begins at sea level in Seogwipo and climbs steadily toward Hallasan National Park before reaching the summit at 1,947 m. From there, the route descends through volcanic forest, lava rock trails, and high alpine terrain toward Jeju City and the northern coast. The route can also be completed in the opposite direction, starting in Jeju City and finishing in Seogwipo.
A reservation is required to access the summit area of Hallasan National Park. Reservations must be made in advance through the official Hallasan reservation system:
https://visithalla.jeju.go.kr/main/main.do
You only need to reserve the trail from which you enter the park. For example:
- If ascending via Seongpanak and descending via Gwaneumsa, reserve Seongpanak only.
- If ascending via Gwaneumsa and descending via Seongpanak, reserve Gwaneumsa only.
The route is fully self-powered and follows public roads, trails, and official park routes. Weather conditions on Hallasan can change rapidly throughout the year, including strong winds, rain, snow, and freezing temperatures near the summit. Runners should carry appropriate gear, check trail opening hours, and confirm summit access conditions before attempting the route.
