Naganeupseong is a Korean castle in Nagan-myeon, Suncheon, Jeollanamdo, South Korea. Naganeupseong is the only remaining Joseon dynasty castle in Jeollanamdo. It finely has the old images of Joseon folk village and castle, with about 100 houses and government offices. Nowadays, there still are 85 households and 229 people living there. It has the biggest feature that it was built on the plain fields and has the narrow stone walls around the castle.