This stunning limestone cave is a rabbit warren of metal catwalks and spiral staircases running through 1.7km of dense, narrow grottoes. It’s quite an intimate experience, where you can get up close with the rock formations. Unlike garishly lit caves, Gosu Donggul feels old and drippy – perhaps not as old as its 150,000 years, but certainly authentic. The cave is a 15-minute walk across the Gosu bridge from Danyang, or catch bus 170 from the bus terminal.
Walkways are narrow, so it's definitely not for the claustrophobic.
Cross the bridge to the tourist information centre and follow the road to the right to a busy tourist village. The cave entrance is tucked away up a stone staircase behind the village. At the village you can refresh yourself with a cup (or jar) of local drinks such as omija (five-flavour berry), honey (꿀; kkul) or yam (마; ma).