Manjanggul Lava Tube

The world's longest lava cave, which means "very deep" in the Jeju dialect. The cave is well-preserved and of great scientific value, and is listed as a UNESCO World Natural Heritage Site. With an average temperature of 12 °C in the middle of summer, visitors can enjoy natural air conditioning, and inside, they can see various lava cave products such as lava stalactites and lava stalagmites, including the world's largest lava columns, which are roughly 7.6 m high.