This is the surface of the wooden pillar of Namsan Outdoor Botanical Garden. Namsan Outdoor Botanical Garden is a botanical garden and arboretum located in Itaewon-dong, Yongsan-gu, Seoul. It is located in the middle of the Namsan Dulle-gil Trail, which is favored by many people, and if you go up the mountain path inside the Dulle-gil from the outdoor botanical garden, you will find Namsan Tower.