The weekend before last I visited Danyang, in the northeast of Chungcheongbuk-do. Situated on a curve of the Namhangang and, when the water's high enough, considered a part of Chungju Lake, there's a lot of natural beauty in the area. Some of it is underground, as there are 4 well known caves in the area. I visited two, the first being Gosu Cave, which is very close to town (on the other side of the Gosu Bridge, just past the tourist information office). It was first explored in the early 1970s, and was found to have been a shelter for humans in the Paleolithic era. It's now home to some pretty spectacular rock formations.
One wonders how much H.R. Giger explored caves; I often felt like I was on the set of an Alien movie.
This photo should give some idea as to how tall the cave gets at points:
Needless to say, those suffering from claustrophobia and fear of heights might want to gove this a pass (as might those with a large belt size - the walkways get very narrow at points).
Four kilometers down the road from Gosu Cave is Cheondong Cave, which was first discovered in the 1970s.
The warnings that apply to Gosu Cave apply even more to Cheondong Cave, as the passageways at times force you to almost crawl, or to descend stairs backwards. Here's a view of the largest room in the cave:
All in all, a fun way to spend 5,000 won. I'll post more about the rest of the trip in a day or so.