Suwolbong Peak

Suwolbong is a low volcanic cone, just 77 m high, on the coast at Gosan-ri at the far western tip of Jeju. The summit itself looks ordinary, but the sea cliffs below expose layers of volcanic ash laid down in an eruption about 18,000 years ago, striped like a cross-section in a textbook, which is why volcanologists treat the site as a reference. From the top you look straight out to Chagwido island and the sunset over the western sea.

A cone made by sea and magma

Suwolbong is a tuff ring, formed when rising magma met water and exploded violently. Along with Seongsan Ilchulbong and Songaksan it is one of Jeju's classic hydrovolcanic cones. During the eruption a turbulent mix of gas, ash and rock fragments raced outward along the ground and settled in layer after layer, a process known as a base surge. As the sea ate away the western side of the cone, the cross-section ended up exposed in the cliffs.

What to look for in the cliffs

• Wavy layers: further from the vent the beds become thinner and ripple like waves. The layers run sideways for so long that they can be matched between distant points, which makes this outcrop rare even by world standards.
• Volcanic bombs and bent beds: look for blocks of rock that fell during the eruption and pressed the layers beneath them into dips.
• Eongal: locals call the shore under the cliffs "eongal" — "eong" means cliff and "al" means below in Jeju dialect. The cliffs run for about 2 km.

The layers were designated a Natural Monument on 11 December 2009 as the Pyroclastic Deposits of Suwolbong, and the site is part of the Jeju UNESCO Global Geopark.

The summit and the name

At the top stand Suwoljeong, a hexagonal pavilion once used for rain rituals, and the Gosan weather station. From the pavilion you see Chagwido just offshore, Sanbangsan in the distance and, on clear days, Hallasan. Two stories explain the name. One links it to a memorial stone put up in 1910 for Go Ji-nam, whose pen name was Suwol; the other to a legend about a brother and sister, Nokgo and Suwol. The hill was therefore also known as Nokgomul-oreum or Suwoli-oreum. Around it stretches the Gosan plain, the widest stretch of flat farmland on Jeju, and the springs that rise at its foot are known for their drinking water.

Rockfalls and closed sections

Layers of volcanic ash are weak, and rockfalls are frequent. On 17 April 2024 part of the cliff near the northern entrance of the coastal path collapsed, and the Eongal coastal trail was closed; sections have remained closed since. Keep away from the base of the cliffs, never cross barriers, and check which sections are open before you go.

Tripto tips

• Access: open at all times and free. Near the summit there is a car park, toilets and a viewing area.
• Best time: sunset is the most popular time. It is a windy spot, so bring a layer.
• Time needed: about 30 minutes for the summit views, 1–2 hours if you also walk the open parts of the coast.
• Nearby: the Eongal coastal path continues to Jagunae port and links to Jeju Olle Trail route 12. Chagwido lies just off Jagunae, and the Gosan-ri prehistoric site is close by.