Manjanggul is a lava tube located in Gimnyeong-ri, Gujwaeup, Jeju City, South Korea. At up to 23 metres wide, 30 metres high and 8.928 km long, it is the 12th-longest lava tube in the world and the second longest on Jeju Island, although a significant portion of the cave is closed to visitors. It is the only cave of the Geomunoreum Lava Tube System, considered one of the finest lava tube systems in the world, regularly open to the public. It is also part of the UNESCO World Heritage Site list, under the item Jeju Volcanic Island and Lava Tubes.
Lava stalactites and lava stalagmites, lava columns, lava flowstone, lava rafts, lava shelves, Among them, a lava column of 7.6 metres is the largest known in the world.
Wikipedia https://en.wikipedia.org/wiki/Manjanggul
Phone +82-64-710-7903
Coordinates 33°31'44.175" N 126°46'17.035" E