In 1972, the United Nations Educational, Scientific and Cultural Organization (UNESCO) adopted the Convention Concerning the Protection of the World Cultural and Natural Heritage. The aim of the Convention was to protect cultural and natural heritage of outstanding universal value to humanity as a whole. China ratified the Convention in 1985. Then between 1987 and 2017, China successfully submitted 52 items for inclusion on the World Heritage List, which included 36 items of cultural heritage and 4 items of mixed cultural and natural heritage.