Yayoi period
Most of the tombs of chiefs in the Yayoi period were square-shaped mounds surrounded by ditches. The most notable example in the late Yayoi period is Tatetsuki Mound Tomb in Kurashiki, Okayama. The mound is about 45 metres wide and 5 metres high and has a shaft chamber. Broken pieces of "Tokushu-kidai", cylindrical earthenware, were excavated around the mound.