Songaksan

At Jeju's southwestern tip, a low volcano juts into the sea, and from its rim Sanbangsan, the Hyeongjeseom islets, Gapado and Marado line up in a row. Songaksan is a double-crater volcano, one crater nested inside another. Under its coastal cliffs, a row of caves dug by the Japanese army at the end of the Pacific War survives, so the walk combines scenery with history.

A volcano with two craters

Songaksan was formed by volcanic activity under the sea. The outer first crater is about 500 m across and 1.7 km around; the inner second crater is about 400 m wide and 69 m deep, dropping almost vertically. Black and red layers of volcanic ash are exposed inside. The south side ends in sea cliffs, and the soil is so dry that apart from some planted pines there is hardly any forest.

What to see

• Songaksan Dulle-gil: A clifftop path with constant views of Sanbangsan, Hyeongjeseom, Gapado and Marado; Jeju Olle Route 10 runs along it.
• Coastal Japanese cave positions: Dug around 1945 by forcibly mobilised islanders, these tunnels were meant to hide small boats for suicide attacks on Allied fleets. Fifteen are registered national heritage.
• Outer-rim positions: A centipede-shaped tunnel network along the first crater's ridge, with 22 known entrances.
• Sea views: On clear days Marado, Korea's southernmost island, looks within reach.

Good to know

• Alddreu Airfield and Seotal-oreum: The Japanese turned the Songaksan area into a military base and built an airfield nearby. During the Korean War, residents rounded up in preventive detentions were massacred at neighbouring Seotal-oreum; the families gathered the intermingled remains into 132 mounds known as Baekjo Ilson Jiji.
• Fishing: The waters off Songaksan are known for black porgy and opaleye.
• Coastal tunnels: Seventeen were dug along the cliffs, in I-, H- and U-shaped plans, and they became registered national heritage in 2006.
• Rim positions: Built to guard the nearby airfield, ammunition depots and hangars and to counter a landing; the tunnels are only 1–2 m wide.
• Remains uncovered: The authorities sealed off and concealed the Seotal-oreum massacre site, but the remains came to light and were excavated in 1957.

Nearby

• Sanbangsan: The massive rock dome to the north, the biggest feature in every view from the trail.
• Marado: Boats to Marado leave from Sanisu-dong Port at the foot of Songaksan.

Tripto tips

• Summit closed: The summit and some trails have been closed under a nature rest period since 2015, currently extended to 31 July 2027. The coastal loop is open.
• Visiting: Free, open 24 hours, with parking.
• Time needed: 1–2 hours for the loop and the coastal positions.
• Take care: It is often very windy; bring a hat and windproof layer, and stay out of the fenced cliff areas.
• When to go: Late afternoon, when the sky over Sanbangsan turns red.