仁徳天皇
Sakai is known for its keyhole-shaped burial mounds, or kofun, which date from the 5th century. The largest of these, Daisen Kofun, is believed to be the grave of the Emperor Nintoku and is the largest grave in the world by area. Once known for samurai swords, Sakai is now famous for the quality of its kitchen knives; most high-quality Japanese cutlery originates in Sakai, and its production is a major industry in the city.