Emperor Ōjin
The biggest kofun are believed to be the tombs of emperors like Emperor Ōjin (応神天皇 "Ōjin Tennō") and Emperor Nintoku (仁徳天皇 "Nintoku Tennō"). Kofun are also classified according to whether the entrance to the stone burial chamber is vertical (縦穴 "tate-ana") or horizontal (横穴 "yoko-ana").