Mounded tombs were still constructed in the seventh century - in some local provinces, even until the eighth century - however, with the year 538 (around when Buddhism was introduced into Japan, they say) being the boundary, the period before this year is called the Kofun period, and the time after this is called the Asuka period.
古墳は７世紀に入っても築造され、地方によっては8世紀まで造られているが、仏教公伝の年とされる538年頃を境に、それ以後を飛鳥時代、以前を古墳時代と呼んでいる。