Judging from the result of examining the age of the artifacts that have been excavated from the site, it is very probable that the remains of the third period were Nochino Asuka no Okamoto no Miya Palace and Asuka Kiyomihara no Miya Palace.
Ⅲ期の後飛鳥岡本宮・飛鳥浄御原宮については出土した遺物の年代考察からかなり有力視されている。