Emperor Nintoku
The third stage in Japanese prehistory, the Kofun period (c. 300 – 710 AD), represents a modification of Yayoi culture, attributable either to internal development or external force. This period is most notable for its tomb culture and other artifacts such as bronze mirrors and clay sculptures called "haniwa" which were erected outside these tombs. Throughout the Kofun period, the characteristics of these tombs evolved from smaller tombs erected on hilltops and ridges to much larger tombs built on flat land. The largest tomb in Japan, the tomb of Emperor Nintoku, houses 46 burial mounds and is shaped like a keyhole, a distinct characteristic found within later Kofun tombs.