日本で最古の重要文化財はなんですか？
By 1929 about 1100 properties had been designated under the "Ancient Shrines and Temples Preservation Law" of 1897. Most of these were religious buildings erected from the 7th to the early 17th century. About 500 buildings had been extensively restored with 90% of costs paid from the national budget. Restorations during the Meiji period often employed new materials and techniques.
In 1929, the was passed and came into force on July 1 of the same year. This law replaced the laws from 1897, extending protection to all public and private institutions and private individuals in order to prevent the export or removal of cultural properties. The focus was extended from religious buildings to castles, teahouses, residences and more recent religious buildings. Many of these structures had been transferred from feudal to private owners following the Meiji restoration. Some of the first residential buildings designated would be the Yoshimura residence in Osaka (1937) and the Ogawa residence in Kyoto (1944).
In addition, the designation National Treasure was applied not only to objects of art but to historical buildings as well. The new law also required permissions for intended alterations of designated properties.
Yoshimura residence in Osaka