Forty-eight archaeological materials or sets of materials from ancient to feudal Japan have been classified as National Treasures of Japan. The term has been used in the country to denote cultural properties since 1897; the definition and the criteria have changed since the introduction of the term. The listed archaeological materials 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 materials, spanning a period from about 4500 BC to 1361 AD, were selected by the Ministry of Education, Culture, Sports, Science and Technology based on their "especially high historical or artistic value". The actual number of items is more than forty-eight because groups of related objects have been combined into single entries. Most of the items have been excavated from tombs, kofun, sutra mounds or other archaeological sites. (Full list...)