Cave CODUGNON CAVE is a natural internal cave, which needs to be drilled into small caves to enter. Unlike Line A and Line C, CODUGNON CAVE has no inland sea, but steep cliffs. To get into the cave, the captain had a life jacket as a cushion, because the rocks were so sharp that they easily scratched our back, hands and legs. Inside the dark cave, there were several beams of light, and a cliff-steep inner cave.