In an excavation of the Heijo Palace Site in Nara, wooden strips were discovered which showed that an abalone about 1.5 m in length was sent as a gift from Awa Province (part of present-day Chiba Prefecture; records on tributes in the "Engishiki" [ancient compendium of laws published in the tenth century] show that Awa Province was well known as an abalone producing region at the time).
また、平城宮跡の発掘では安房国より長さ4尺5寸（約1.5m）のアワビが献上されたことを示す木簡が出土している（安房国がアワビの産地であったことは、『延喜式』主計寮式にも記されている）。