A Cool Summer Walk on Hallasan: Gwaneumsa Trail & a Hidden Natural Wind Hole

entrance gate to Gwaneumsa forest trail Hallasan
Entrance to the Gwaneumsa forest trail · Photo © sunny

Living on Jeju, I barely go near the beach in summer. Too crowded, too much sun. Instead, I head for the mountains, and this time I chose the Gwaneumsa trail on Hallasan.

There's really one reason I'm writing about this route today. Partway through, there's a spot almost nobody notices — a natural air conditioner tucked into the rock. Sitting in front of that cool air, summer stopped feeling real. More on exactly where it is below.

I wasn't hiking to the summit. My destination was Tamnagyegok Valley, and everything about this walk was built around getting there slowly.

Tamnagyegok, the valley partway up this trail, is dry most of the year, and it was dry when I went too. But that's fine. The coolness of the forest and mountain air is enough on its own, water or not.

People assume Hallasan means a pre-dawn start. I left home around 10am, because this time I wasn't going for the summit — just Tamnagyegok Valley. In summer, I'd rather show that a gentle stretch of trail is plenty, without pushing for the top.

From the Gwaneumsa entrance to the wooden bridge, the path is flat forest walking with almost no incline — easy for anyone. Shade covers the trail the whole way, so it stays cool the entire time.

Gwaneumsa trail entrance parking lot Jeju
Parking lot at the Gwaneumsa trail entrance · Photo © sunny
hiker walking Gwaneumsa forest trail Hallasan
Walking the shaded Gwaneumsa forest path · Photo © sunny

A Natural Air Conditioner Almost Everyone Walks Past

This is the part of the hike I most wanted to share. I hesitated for a second, honestly — half-worried this spot would get crowded once people knew. But good things are meant to be shared.

Walking the forest path, you'll pass a signboard that reads "Forest and Atmosphere." Turn left right at that sign and you'll find a pungyeol — a natural wind hole where cool air seeps out from cracks in the rock. It's close to the entrance, appearing before the "National Point Number 5-1" marker. There's no official signage pointing to it, so most people just walk by. I did too, for a while, before finally noticing it this time.

Forest and Atmosphere signboard wind cave turnoff Hallasan
The "Forest and Atmosphere" sign — the wind hole turnoff is to the left · Photo © sunny
hidden natural wind cave entrance Hallasan Jeju
The wind hole, with no signage to mark it · Photo © sunny

Cool air just flows straight out of the cave — a genuine natural air conditioner. I measured it myself: 15.9°C right outside the cave, 10.2°C just inside, a real difference. Humidity read 66%. I'd been sweating on the way down, so sitting in front of that air felt like I'd stumbled onto heaven. I honestly didn't want to leave. I think I sat there for a good 20 to 30 minutes.

temperature reading inside Hallasan wind cave
Measured temperature — 15.9°C outside, 10.2°C inside the cave · Photo © sunny
rest bench in front of wind cave Hallasan trail
A small rest spot right in front of the wind hole · Photo © sunny

Past the wind hole, National Point Number markers start showing up along the trail.

National Point Number marker Gwaneumsa trail Hallasan
A "Gwaneumsa 5-1" National Point Number marker · Photo © sunny
☀️ Sunny's Tip Here's how to read these markers: for "Gwaneumsa 5-1," the first number marks the Gwaneumsa route, and the second climbs by one every 250m. So just glancing at that second number tells you roughly how far you've come. The yellow coordinates underneath are part of Korea's National Point Number system — a nationwide grid used to pinpoint locations for emergency rescue, especially in places without a street address, like mountains.

Gurin Cave — Once Used to Store Ice?

Keep walking a bit further and you'll reach Gurin Cave, a 442-meter lava tube with an entrance about 3 meters wide. Old Jeju records mention a rock cave on Hallasan that was once used to store ice year-round for the local government office. Some historians believe Gurin Cave may have been the lava tube mentioned in those old records, although it has never been confirmed. Traces of old dwellings and charcoal kilns have also been found nearby. According to the national park, it sits at the highest elevation of any cave on Jeju and is home to a range of cave-dwelling creatures and bats, giving it real academic value.

mossy entrance Gurin Cave Hallasan lava tube
Gurin Cave's mossy entrance · Photo © sunny
viewing deck Gurin Cave Gwaneumsa trail Jeju
The viewing deck in front of Gurin Cave · Photo © sunny

The Wooden Arch Bridge Is Enough for Most People

Keep going and you'll reach Mokgyo, an arched wooden bridge. Everything up to here is gentle enough for anyone, any age, to walk without strain. Just sitting on a bench near the bridge and taking in the forest air felt like plenty of a reset. A lot of people I saw turned back right here.

trail map sign near Mokgyo bridge Gwaneumsa Hallasan
Trail map sign near Mokgyo · Photo © sunny
Mokgyo wooden arch bridge Gwaneumsa trail
Mokgyo, the arched wooden bridge · Photo © sunny

The Final Stretch to Tamnagyegok Valley

Past the bridge comes the one real challenge on this route — around 120 stone steps in a row. Climb those and you'll reach Tamnagyegok Valley itself. Then you'll find the restroom and a raised wooden rest platform waiting. If you need a restroom, or just want to sit longer, it's worth pushing through this stretch.

stone stairs to Tamna Valley restroom Hallasan trail
The roughly 120-step stretch of stone stairs · Photo © sunny
Tamna Valley restroom and rest platform Hallasan
Restroom and rest platform at Tamnagyegok Valley · Photo © sunny

From the Gwaneumsa entrance to this restroom is about 3.2km, usually around 1 to 1.5 hours. We went slowly and rested at the bridge too, so it took us closer to 1.5 hours.

I climbed the stairs mostly for the exercise, ate the snacks I'd packed on the wooden platform, and headed back down.

You Don't Even Have to Hike

Near the Gwaneumsa entrance, there's a camping ground and rest platforms where plenty of people escape the heat without hiking a single step. I saw people stretched out on mats, families just sitting on the platforms passing the time.

lawn rest area Gwaneumsa entrance Hallasan Jeju
A rest spot at the entrance, no hiking required · Photo © sunny
☀️ Sunny's Tip One thing worth knowing: the campground itself charges a fee, but the shaded rest platforms right next to it are free to use. If you're just there to cool off, you don't need to pay anything.

You don't have to reach the summit to enjoy Hallasan. In summer, I'd actually recommend this route over anything higher up. Walk only as far as the bridge, or just sit in front of the wind hole and let the air do the work — either way, it's enough.

📍 Address 588 Sanrokbuk-ro, Odeung-dong, Jeju City, Jeju Island
🚶 To the wooden bridge Gentle forest path, easy for anyone
🚶‍♀️ To Tamnagyegok restroom About 3.2km · 1 to 1.5 hours
🚗 Parking Public parking available (a new hourly-increment fee applies from 2026 — check the exact rate before you go)
🏪 Shops No shops along the entire trail — bring water and snacks
📍 Hallasan National Park Gwaneumsa Trail Center
🏠 Odeung-dong, Jeju City, Jeju Island

☀️ Sunny's Note

As a local resident of Jeju Island, I explore places in person and share my honest experiences, travel tips, and photos whenever possible. I continue to update my guides with new information and changes that may help your Jeju trip.


🌿 Continue Exploring

👉 Jeju Nature Guide: Hallasan, Forest Trails & Oreums

Comments