Seoraksan's Heullimgol trail goes booking-only — 1 Oct to 30 Nov

Under a notice the Seoraksan National Park Office issued in June (No. 2026-19), the Heullimgol trail in southern Seorak goes back to booked entry for two months from 1 October. Until the end of September you can walk it without a booking as long as you keep to the park's entry hours; from October, anyone without a time slot booked on the national park reservation system is turned away at the gate. Heullimgol reopened after safety works that followed a 2015 rockfall, and the park manages it by capping numbers and staggering entry times. The booking period lines up exactly with the autumn colour season, so anyone planning to climb Seoraksan from the Osaek side this autumn needs to know this first.

When does the Heullimgol booking period run?

The notice sets two booking periods this year: 1 January to 23 June (146 days) and 1 October to 30 November (61 days). The trail was closed outright from 4 to 31 March for the spring thaw. From 24 June to 30 September no booking is needed and only Seoraksan's designated entry hours apply (3am to 2pm in summer). The notice says that from 2027 the booking system will run in October and November only, and the reservation site's trail page already describes it that way: bookings in October and November, open access the rest of the year. Both add that the dates can change with conditions on the ground.

How do you book Heullimgol?

1. On the national park reservation site (reservation.knps.or.kr), go to the trail-reservation menu and pick 'Seoraksan Heullimgol'. You need to be logged in as a member of the park service's website.
2. Choose a date, then a one-hour entry slot: between 8am and 3pm in October, 9am and 2pm in November.
3. Booking closes at 2pm the day before. You cannot book online on the morning itself.
4. All places are allocated online; only what is left is released at the Heullimgol Trail Support Center on the day. On an autumn weekend, do not count on a walk-up place.
5. Booking questions go to the reservation line on 1670-9201 (weekdays 9am–6pm, closed 12–1pm); conditions on the trail to the Osaek ranger station on 033-801-0973 or the Seoraksan National Park Office on 033-801-0900. All three answer in Korean.

As of 26 September the booking calendar shows dates from 1 to 31 October. November dates are not on the calendar yet, so check again if you plan to go in November. The notice says that entering during the booking period without a booking is subject to a fine under the Natural Parks Act.

How long is the Heullimgol course? 3.1 km, one way

The booked section is a single stretch from the Heullimgol Trail Support Center to the Yongso Falls junction, which the official page gives as 3.1 km one way, about 2 hours 30 minutes. It is walked in one direction only, so you cannot start from the Yongso Falls end or turn back halfway. Because it starts and finishes in different places, that shapes where you leave a car, so settle the route before you set off.

From the support center the path passes Yeosim Falls, Deungseondae, Deungseon Falls and Sibi (Twelve) Falls before reaching the Yongso Falls junction. Yeosim Falls, early on, is easy to recognise: a thin stream dropping through a split in the rock.

The stretch from Yeosim Falls up to Deungseondae is short but steep. At the top, the spiky ridges known as the 'Manmulsang of southern Seorak' spread out on every side, and this is where most people linger longest. The trick is not to spend all your energy getting there.

Below Deungseondae the path follows the valley. Around Deungseon Falls and Sibi Falls the water comes down between granite walls in several steps and the valley floor is strewn with boulders, so go slowly and watch your footing.

What safety rules apply on Heullimgol?

The trail page and the booking screen both put safety ahead of numbers. Heullimgol is where a rockfall happened in 2015, and the park says that even after reinforcement work, the terrain of Seoraksan means rockfall remains a constant risk. The park lists 22 weak points along the route, each fitted with a flashing warning light, and asks walkers to pass them quickly.

• At the weak points marked by warning lights, do not stop to rest or take photos; keep moving.
• If a weather warning for heavy rain or a typhoon is issued, or the weather turns, stop and come down. As the name suggests, Heullimgol ('the misty valley') is often foggy and overcast.
• The route is one way, so turning back is hard. Before starting, weigh up your energy and the time of sunset.
• Entering in the last slot (3pm in October, 2pm in November) means a late finish. Days are short in November, so an early slot is the safer choice.
• The booking screen asks you to pass these warnings on to anyone booked with you.

When should you book for the autumn colours?

Seoraksan is one of the first mountains in Korea to turn, and the colours usually peak around mid-October. That is why the booking period is October and November, and why October, with its hour-longer entry window, is set apart as the autumn peak season. A 5,000-a-day cap is not small, but morning slots on October weekends and holidays can go quickly. Book as soon as your date is fixed, and check this year's peak on the Korea Forest Service's autumn foliage forecast.

After the Yongso Falls junction: Jujeongol and Osaek

The booked section ends at the Yongso Falls junction, but most people carry on down the Jujeongol valley to Osaek Mineral Spring. This valley path, past Geumgangmun, Seonnyeotang pool and Yongso Falls, is gentler than Heullimgol and makes a good way to finish. It is not part of the booking system, but the entry-hour rule still applies: no walking from sunset until two hours before sunrise the next day.

Where do you park?

There is no car park near the Heullimgol Trail Support Center. The official page says use the Osaek village car park and do not stop on the verge of Route 44 (the Hangyeryeong road), and the booking screen warns that illegal parking inside the park can be fined. The one-way route makes the plan simple: leave the car in Osaek, take a taxi or bus up to the Heullimgol Trail Support Center, then walk back down through Heullimgol and Jujeongol to Osaek, where the car is waiting.

Getting there, booking from abroad, and what is in English

Osaek, in Yangyang County on the east side of the Taebaek ridge, is where the day starts and ends. Without a car, the usual approach from Seoul is an intercity bus from Dong Seoul Bus Terminal towards Yangyang that runs over the Hangyeryeong pass via Osaek; timetables change by season, so check the current one before you go. From Osaek a short taxi ride takes you up Route 44 to the Heullimgol trailhead. Drivers should head for the Osaek village car park, not the roadside at the trailhead.

The booking is the hard part. The park service's English reservation site covers shelters and campsites only; the Heullimgol trail can only be booked on the Korean-language site, and doing so needs a member account on the park service's website, which uses Korean real-name verification (a Korean mobile number or an I-PIN). A short-stay visitor with no Korean phone number will usually not be able to complete that alone. The realistic options are a Korean-speaking friend or your accommodation booking on your behalf, or arriving early on a weekday and hoping for leftover places at the trailhead, which is a gamble in October. If you are in Korea before 30 September, the trail is open without a booking until then.

On the trail itself you need no Korean: the route is one way and hard to lose, and the warning lights at hazard points speak for themselves. The safety notices on the booking site and the three enquiry lines are in Korean only, so read the rules on this page before you go.