Jeju is a volcanic island, and wherever you go there are plenty of rocks. Porous basalt and soft trachyte are particularly common. The people of Jeju used stone to make many of the items they needed in their daily lives.
The outdoor exhibition space of Jeju National Museum displays items like jeongnang (gates installed in front of private homes), maetdol (millstones), and yeonjamae (grinding stones) that were made and used by the people of Jeju in the past, as well as dongjaseok (child statues) that were erected in front of graves. You can also view reproductions of the five-story pagoda from the site of Wondongsa Temple (a cultural treasure), dolhareubang (stone statues) from Jeju Eupseong (walled town), and Dongjabok and Seojabok (Jeju Special Self-Governing Province Folk Cultural Treasures, the stone statues which stood on the east and west sides of the old Jeju Castle gate).