It's in front of Nanta Lake. Admission is 5,000 won per person. Visit at 7:30 p.m. to view 4D for 5 minutes, but it's so much fun. The explanation of the stars is catchy, and the weather is clear, so seeing the constellations is more fun than I thought.
GO AT NIGHT. YOU'RE WELCOME. It was unexpectedly fun! We loved it! I'm gonna take my family there, but it's also fun with friends or a date. You get the classic elementary-school info for kids but, if there's no clouds, you also will watch the moon and the easiest-to-see planet at the moment with some info about constellations and stuff. It's a beautiful and interesting place. But, disclaimer, get ready to use your translator because most of the people who goes there are locals, so all the info is in Korean and I didn't see any guidance in English.