To protect Japan's cultural heritage, the country's government has established with the Law for the Protection of Cultural Properties a "designation system" (指定制度?) under which it selects important items and designates them as Cultural Properties,[note 2] imposing restrictions to their alteration, repair and export. Besides the "designation system", there exists a "registration system" (登録制度?), which guarantees a lower level of protection and support to Registered Cultural Properties.
Cultural Properties are classified according to their nature. Items designated as Tangible Cultural Properties (as opposed to Intangible Cultural Properties), cultural products of high historical or artistic value such as structures, paintings, sculptures, handicrafts, calligraphic works, ancient books, historic documents, archeological artifacts and other such items, can later, if they satisfy certain criteria, be designated either Important Cultural Properties or National Treasures(国宝?), for especially valuable items. The designation can take place at a city (市定重要文化財,city designated Important Cultural Property?), prefectural (県定重要文化財,prefecturally designated Important Cultural Property?) or national (国定重要文化財,nationally designated Important Cultural Property?) level. In this last case the designating agency is often not specified. Designations of a different level can coexist. For example, Sankei-en, a traditional Japanese-style garden in Naka Ward, Yokohama, owns both city designated and nationally designated Important Cultural Properties.