The World Heritage Programme was created by the World Heritage Committee of UNESCO to identify, celebrate, and protect important universal, cultural, and natural sites for the benefit of all humankind. World Heritage Properties are divided into three classes: Cultural, Natural, and Mixed (both Cultural and Natural). A World Heritage site indicates a place where such valuable properties are located. Among the thirteen Korean properties inscribed and recognized by UNESCO, twelve are Cultural and one is Natural.
 

  The Korean World Heritage sites are mainly distributed in the central capital area (five sites) and Gyeongsangbukdo (three sites). Because Seoul has functioned as the capital of Korea since the Joseon Dynasty (1392-1910), several historical sites are found here, such as the Changdeokgung Palace Complex, the Confucian Shrine (at Jongmyo), and the royal tombs of the dynasty. The military facilities located around Seoul also functioned in defense of the capital, and chief among these are the Hwaseong Fortress and Namhansanseong.
 

  Gyeongju in Gyeongsangbuk-do is also noteworthy as an important historical spot. As the capital of the ancient kingdom Silla (57 BC–935), Gyeongju still possesses a variety of historical relics from ancient times such as the Seokguram Grotto and Bulguksa Temple. Additionally, in Gyeongsangbuk-do there are historical villages dating back to the early Joseon Dynasty. Meanwhile, there are two heritage sites in North Korea (the Historic Monuments and Sites in Gaeseong, and the Complex of Goguryeo Tombs). Other provinces also have one cultural site each (Gyeongsangnam-do, Jeolla-do and Incheon). In particular, the volcanic nature of the Jeju Special Self-Governing Province led to it being designated as a World Natural Heritage Site, which is called “Jeju Volcanic Island and Lava Tubes”. It is divided into the Hallasan Natural Reserve, the Geomunoreum Lava Tube System, and the Seongsan Ilchulbong Tuff Cone.
 

  The heritage sites can also be categorized by function. First, there are various types of complex tombs such as the Gochang, Hwasun, and the Ganghwa Dolmen Sites of the Bronze Age, the Goguryeo Tombs of the Goguryeo period, and the Royal Tombs of the Joseon dynasty, all of which account for 27 percent of the designated sites. The tombs reveal snapshots of the culture, the worldviews and the rituals of each period. The proportion of buildings (23.7%) on the list is also high. The various buildings in Changdeokgung, for instance, are well coordinated with the surrounding nature. Designed to control temperature, humidity, and ventilation, Janggyeong Panjeon in Haeinsa Temple still contains the perfectly preserved Tripitaka Koreana woodblocks which have been housed there for the past half millennium. Gyeongju and Gaeseong, the former capitals of the Silla and Goryeo periods, have many historic monuments and sites.
 

  There are a variety of historical buildings, monuments, and ruins that represent each age. Along with Ganghwa and Gaeseong which were designed as military bases to defend Seoul from the west and the north, two other fortresses, Namhansanseong and Hwaseong, are World Heritage Sites. These played a critical role in defending the capital from the east and the south, and both are additionally significant for historical and architectural reasons.
 

  The Korean folk villages of Hahoe and Yangdong, and the royal shrine in Jongmyo are also worthy of notice. The villages remain in keeping the Korean traditional customs in the daily lives of those dwelling there. Programs at the royal shrine demonstrate the Confucian traditions of the royal family in the Joseon dynasty by means of various performances such as rituals, music, and dance.