Suwolbong is located in Gosan-ri, Jeju Island (West side of Jeju Island). It is 77m high and serves as an obervatory for the west region of Jeju city, offering dramatic views of both the land and the sea. Its steep seaside cliff, called Eongal, is about 2km long to the eastward, Nokomul is well known as a mineral spring as natural springs are founding along the cliff.
It’s one of numerous volcanic edifices on Jeju Island. However, the outcrops of the volcanic deposits exposed along the coastal cliffs can act as a volcanology textbook because they show a variety of depositional structures that can be found in volcaniclastic rocks, including planarbedding formed by layer-by-layer accumulation of volcanic ash and bedding sags formed by the impact of falling volcanic blocks.
Suwolbong was part of a tuff ring composed, appox. 18,000 years ago, of volcanic ash, which erupted and then built up around a vent, where hot ascending magma explosively interacted with groundwater. Volcanic ash spread around Suwolbong became rich soil for plants compared with hard lava, which provided ground of life for humans in the Neolithic Period.