Lots of dramas/movie were filmed here apart from SFD, like the King and the Clown, Empress Ki, The One Who Came from the Stars, JSA… I think the most attractive points is that it is easy to go to and there is a DMZ like set there.
For SFD, according to one of my FB followers who went to this place, the scene where Gil Taemi and Yi Banggi fought each other was filmed here.
Just get off Ungilsan Station, and you can get a shuttle bus to get there. Shuttle buses leave Ungilsan Station at 1025, 1125, 1325, 1425, 1625 (1525 in winter). And buses leave the studio at 1100, 1300, 1400, 1600 (1500 in winter), 1810 (1710 in winter). Please check the updated timetable here on their website.
Folk Village for filming SFD
Pic Cr: KOFIC Namyangju Studio web, Korea Tourism Organisation