Hyeopjaegul

Hyeopjaegul is a notable lava tube located within Hallim Park on the southern coast of Jeju Island, South Korea. Jeju Island itself is a massive volcanic shield volcano. The lava tube is part of the Geomunoreum Lava Tube System, which is recognized as a UNESCO World Heritage site.

Hyeopjaegul is highly unique because, unlike most dry lava tubes, it contains secondary carbonate speleothems like stalactites and stalagmites. These limestone formations were created by water percolating through overlying shell-rich sands. This combination of volcanic formation and limestone deposits makes it extremely rare in geology.

Yes, Hyeopjaegul cave is fully accessible to tourists visiting Hallim Park on Jeju Island. Visitors can walk along constructed paths to view the fascinating rock formations, the carbonate deposits, and the various lava formations like lava toes. It is a must-see geological attraction for anyone visiting South Korea.

The Hyeopjaegul lava tube was formed thousands of years ago when highly fluid, basaltic lava flowed from a volcanic eruption. As the outer edges of the lava flow cooled and hardened, the hotter interior continued to flow, eventually leaving a hollow, cylindrical cave behind. The unique shell-sands covering the area later washed into the cave, creating its rare limestone features.