Ulleungdo Island

Character

Ulleungdo rises from an underwater volcanic edifice roughly 3,000 metres high, though only its uppermost 982 metres stand above the East Sea. That submerged scale helps explain the island seen today: a compact cone with steep coastal walls, deeply cut slopes and a collapsed centre around Nari Basin

The basin is the major exception to the island’s vertical terrain. Geological research reconstructs Nari as a multi-stage caldera formed by repeated collapse after explosive eruptions; its topographic rim is about 3.4 kilometres wide, with roughly 750 metres of accumulated downward displacement along ring faults. The result is an unusually broad interior floor enclosed by steep volcanic walls

Around the coast, erosion has worked the same volcano into sea cliffs, stacks, arches, caves and narrow shore platforms. Academic geomorphology identifies those forms alongside the caldera and central cone as defining elements of Ulleungdo. The island therefore changes quickly between enclosed interior basin, high forested ridges and exposed coast within short straight-line distances

That terrain also governs infrastructure. Ulleung County’s council describes passenger shipping as the island’s only public-transport link with the mainland. On land, the coast road became a complete circuit only in March 2019, when the final missing section opened. Geography that reads as spectacle to a visitor has long been a transport constraint for residents

The experience

Ulleungdo works as an area rather than a single attraction. Sadong is one current ferry gateway; the Nari Basin opens a very different interior landscape; Seonginbong gives the island its highest mountain route; coastal trails expose volcanic rock almost at water level

The Dodong coastal trail makes the geological sequence unusually easy to see without a summit hike. VISITKOREA describes exposed basaltic lava, sedimentary and pyroclastic layers, ignimbrite and trachyte along the coast, with the rock sequence changing toward the lighthouse. The walk turns a section of shoreline into a cross-section through repeated volcanic activity

Nari Basin changes the physical rhythm. Flat cultivated and settled ground sits inside the caldera while steep walls rise around it. Research on the basin’s hydrology shows how that enclosed form also concentrates drainage toward the Choosan spring area, where large volumes of groundwater emerge near the point where the flat basin floor gives way to a steep northern outlet

Movement between these environments takes time despite the island’s modest size. Roads follow the available coast and mountain passes, while hiking routes add another layer of vertical travel. Reaching Nari, the north coast and Seonginbong requires separate movement away from the ferry gateway

History

Ulleungdo’s geology records repeated volcanic episodes extending through the Quaternary. A 2020 study of Nari Caldera identifies at least two major collapse-forming events within the last roughly 40,000 years. Older volcanic units, later explosive deposits and subsequent erosion produced the island’s present combination of central basin, ridges and dissected coast

Human occupation has also been shaped by isolation. In 1882, inspector Lee Gyu-won was sent to Ulleungdo and recorded its settlements and living conditions. Ulleung County records that his inspection helped lead to the government’s 1883 pioneering order, a major step in the island’s modern settlement history

Transport remained a defining constraint long after permanent settlement expanded. The ring road project sought to connect communities around coastlines where cliffs had interrupted land movement; the final missing section opened in 2019. Even with that road complete, mainland mobility remains maritime. In a 2025 council statement, Ulleung County described sea routes as essential not only for visitors but for medical travel, education, supplies and ordinary resident life

Current ferry infrastructure reflects that dependence. Ulleung Cruise operates between Pohang’s Yeongilman Port and Sadong Port and publishes live monthly sailing calendars. Its timetable also shows cancellations and maintenance periods, making sea conditions and vessel operations part of the travel system rather than an incidental inconvenience

Before you go

Ulleungdo has no single entrance after arrival, and ferry port choice affects the first movement on the island. The current Ulleung Cruise route arrives at Sadong; Dodong and other bases require onward transport from there. Passenger identification and early terminal arrival are part of the boarding process

The island itself has no closing time or general admission fee. Individual trails, cable cars, museums, ferries and other facilities keep their own schedules and charges. Sea conditions can alter ferry plans, while individual attractions retain their own operating rules