There is a 3 hole short course behind the Admiral Hotel, however you have to be a member to play there.
There is a 6 hole course, which you can play 3 rounds on at Deokpo, up over the hill and past the International Park. They also have a driving range.
There is a new 18hole course called Debeach, which is up on the north of the island towards Jangmok.
There are also several places where you can play screen golf, the best of which is Called Masters, oposite Il Bueno Cucina Restaurant behind 4 fish mart.