To go to Eco Green Campus, first go to Gangbyeon station and take bus (12300W) from East Seoul Bus Terminal to Hoenggye 횡계 (this is not the last station of the bus), and then take taxi to the ranch (about 15000W).
There are two ranches in Daegwallyeong, the bigger on is Eco Green Campus, and that is where the scenes where Bang Won chased Boon Yi in episode 6 and Bang Ji and Yeon Hee met each other again in episode 9 were filmed. The scenery are different yet beautiful in all four seasons, and it is worth visiting on its own merit. K drama that are filmed here including Yong Pal, Beethoven Virus, Autumn in my Heart. (The smaller sheep farm is called Daegwallyeong Sheep Farm, that is different from this one.)
Korean beef there in Hoenggye is very famous and cheaper than in Seoul, remember to try it while you are there.
Photos from SBS