Sakai City is home to the Imperial Mausoleum of Emperor Nintoku, one of the world’s three great tombs, which was registered as a World Heritage Site in July 2019. 1,600 years ago, the construction of the Nintoku Imperial Mausoleum, the largest in Japan and the pride of Sakai, required an enormous amount of human power and tools. The manufacture of these tools required iron and hoe processing techniques, and many craftsmen were gathered from all over Japan, giving birth to Sakai’s iron culture. It is said that these skills contributed to the development of guns, swords, kitchen knives, and the bicycle industry. For kitchen knives, the division of labor has been established since long ago, and knives are carefully finished in the forging, sharpening, and handle attachment processes, and more than 95% of the cooking knives used by professional chefs are made in Sakai. Sakai is also home to Japan’s only “Bicycle Museum” and the Sakai stage of the “Tour of Japan,” the country’s premier bicycle race. In addition, the kelp processing industry, including “Tororo” and “Oboro,” developed as knife skills were refined, and kelp is counted as one of Sakai’s specialties, and Sakai is at the center of the “Kelp Road”.