Manjang-gul is the main access point to the world’s longest system of lava-tube caves. In total the caves are 7.4km long, with heights between 2m and 23m. In this section you can walk around 1km underground to a 7m-high lava pillar, the cave’s outstanding feature. The immense black tunnel with swirling walls looks like the lair of a giant serpent and it’s hard to imagine the geological forces that created it aeons ago, moulding rock as if it were Play-Doh.
Take a jacket and good shoes, as the cave ceiling drips, the ground is wet and uneven and the temperature inside is a chilly 10°C, regardless of the weather outside. The lighting is dim so a torch (flashlight) is a good idea. The ticket office is about 2.5km from the Entrance to Manjang-gul bus stop on Rte 1132 Iljudong-ro, at the intersection with Woldeong-ro; a transfer to local bus 711 (₩1200, hourly) is possible, but arrival times are inconvenient. A taxi from Gimnyeong costs ₩7000.