Hyeopjaegul Cave is a representative lava cave in Jeju Island, along with Hwanggeumgul Cave, Socheongul Cave, Ssangyong Cave, and Manjanggul Cave. The cave is approximately 200m long, 10m wide, and 5m high, and was created 25 million years ago when a volcano in the Hallasan area erupted. It is unique in that it is a two-dimensional cave that combines the characteristics of a lava cave and a limestone cave, and the area is made up of a sand and shell mixed layer. Inside the cave, stone bells extending from the ceiling and stalagmites that look as if they are rising from the floor create a mysterious scene, and the stalactites that form a single pillar when stone bells and stalagmites meet are both bizarre and beautiful.

The cave The walls are covered with limestone, giving them a magnificent appearance as if they were engraved with a huge mural. The temperature inside the cave is maintained at 17-18℃ throughout the year, making it a unique summer resort in the middle of summer, and in the middle of winter, the cave is in the spotlight because the warm temperature allows you to avoid the cold. Hyeopjaegul Cave is designated as a natural monument, and is so famous that it is considered one of the third wonders of the world, along with the Stone Salt Cave of Peru and the Underwater Lime Cave of Yugoslavia. When you come out of Hyeopjaegul, Ssangyong Cave is located right next to it, so you can tour both caves together.