Gyeongju is the main destination in South Korea for visitors interested in the cultural heritage of Silla and the architecture of the Joseon Dynasty (1392–1910). The city has 31 National Treasures, and Gyeongju National Museum houses 16,333 artifacts. There are four broad categories of relics and historical sites: tumuli and their artifacts; Buddhist sites and objects; fortresses and palace sites; and ancient architecture. Prehistoric remains including Mumun pottery have been excavated in central Gyeongju, in the Moa-ri and Oya-ri villages of the Cheonbuk-myeon district, and in the Jukdong-ri village of the Oedong-eup district.