There were no tumuluses that could possibly have been built around that time (early to mid-Kofun period (tumulus period)), nor were there any grave mounds from the Yayoi period.
その上、そういった当時（古墳時代前～中期頃）に築造された可能性のある古墳もなければ、さりとて弥生時代の墳丘墓と見られるものもない。