Danyang

Gosu Cave 고수동굴
Chungcheongbuk-do Danyang-gun Danyang-eup Gosu-ri
W4000
? to 5:20 PM
Cross the bridge, turn left and walk 10 minutes along the highway

One of Korea's most famous caves, 1.7km of twisting, turning limestone caverns have been outfitted with metal walkways and subdued lighting. It's quite a remarkable sight, but claustrophobes and people in need of a diet might want to skip it as some tunnels are quite narrow.