The most peaceful park in South Korea is, ironically enough, located around a volcano. Named Hallasan, this beast of a mountain is massive enough to bring the entirety of Jeju Island (the last paradise in Korea) to its complete and utter destruction. With an elevation of nearly 2000 meters and an area of 150 square kilometers, this volcano/park combo has a dominating presence, literally looming at you wherever you go on the island.
With all that said however, it’s quite a lovely place.
There are six hiking trails here and the park is big enough for you to detach from the populous and find yourself in complete solitude – somewhat of a rarity in Korea. Make sure to arrive early as certain parts close by 4pm.