Seongsan Ilchulbong (Sunrise Peak)

Seongsan Ilchulbong Tuff Cone (城山日出峰, Seongsan Ilchulbong) formed from volcanic ash that piled up when magma from underground met seawater and exploded. Because the ash was wet, it did not slide down but built up in steep layers. It was an island at first, but sediment worn away by the waves built up and joined it to the main island of Jeju. It was called Seongsan because it looks like a huge fortress, and the name Ilchulbong ("sunrise peak") was added because its sunrise is so beautiful.

In 2000 the peak and the sea within 1km around it became the natural monument "Seongsan Ilchulbong Natural Reserve". 127 species of seaweed and 177 species of marine animals have been recorded in these waters. In 2007 it was inscribed as a UNESCO World Natural Heritage site together with Hallasan and the Geomunoreum Lava Tube System. Traces of Japanese military installations from the Japanese colonial period remain around the peak, and the Teojinmok area that links it to the main island carries the pain of the Jeju 4·3 Incident.