수락산-5(Suraksan-5)
The five mountain ridges that traverse the five mountains attached to Seoul, Mt. Bulam, Mt. Surak, Mt. Sapae, Mt. Dobong, and Mt. Bukhansan, are 43 km long and are also the wish of climbers to climb the mountain quite a bit. I don't know when the day of that challenge will come, but it's a course I want to go to at least once.