High Quality Content by WIKIPEDIA articles! The term "National Treasure" has been used in Japan to denote cultural properties since 1897. The definition and the criteria have changed since the introduction of the term. These ancient documents adhere to the current definition, and have been designated National Treasures since the Law for the Protection of Cultural Properties came into effect on June 9, 1951. The items are selected by the Agency for Cultural Affairs, a special body of the Ministry of Education, Culture, Sports, Science and Technology, based on their "especially high historical or artistic value". "Ancient documents" is one of thirteen categories of National Treasures recognized by the agency. The list presents 60 documents or sets of documents from classical to early modern Japan, from the Asuka period to the Meiji period. The actual number of items is more than 60 because groups of related objects have been combined into single entries. The list contains items of various type such as letters, diaries, records or catalogues, certificates, imperial decrees, testaments and maps. The documents record early Japanese government and Buddhism including early Japanese contact with China, the organization of the state and life at the Japanese imperial court. They are housed in 14 Japanese cities in temples (35), museums (13), libraries or archives (5), shrines (3), universities (2) and in private collections (2). Most entries (28) in the list are located in Kyoto. The documents in this list were made predominantly with a writing brush on paper and, in many cases, present important examples of calligraphy.