Seongsan Ilchulbong is a volcanic peak rising from the sea in eastern Jeju, in Seogwipo, and is designated a UNESCO World Natural Heritage site. From the top, you look down into a bowl-shaped crater and over the eastern Jeju landscape. The uphill path of stairs and wooden decks takes about 20 minutes at an easy pace, and there is a free walking trail to the left of the ticket office. The slope is steady and the stairs are numerous, so your legs do the work.