In 1961, the excavation work performed by Tokutaro YAMANE and his collaborators unearthed the remains of Daigokuden (Council Hall in the Imperial Palace) in 'the late Naniwa no Miya Palace' of the era of Emperor Shomu and its existence was confirmed.
1961年（昭和36年）、山根徳太郎らの発掘により、聖武天皇時代の「後期難波宮」の大極殿跡が発見され、その存在が確認された。