Seonyudo Park sits on an island on the Han River in Seoul, Korea between Hapjeong and Dangsan and is one of the best kept secrets in Seoul. The island, only accessible by foot bridge, walking, or bus, used to house a water treatment plant but in the effort to bring green space back to Seoul, it was released back to nature. Just south of the popular art and live music district known as Hongdae sits Seonyudo Island. There are only a few islands on the Han River that are accessible and this park is one cool one to find. Crossing the bridge from Hapjeong Station to Dangsan Station, I’ve seen…