This trail is a nice little section of trail not far from Kunsan Airbase. Along the way, there's plenty of steep climbing but fun sections on the way down and some views along the way make it all worthwhile.
To access the start of this trail, it is best to take the road about half way up a decent hill to a place where you'll see a steep dirt road to the left before the road starts to descend. Keep an eye out for the trailhead on the right.
This route only goes to the first summit, and features a brief climb followed by a short plateau before a steep and fun descent. If you want to extend your ride, other dirt trails in the area exist.