Located in the center of Hyogo Prefecture, the Ikuno Silver Mine was controlled and developed by the so-called Three Unifiers of Japan: Nobunaga Oda, Hideyoshi Toyotomi, and Ieyasu Tokugawa. These three men determined the fate of Japan as it transitioned from the Sengoku (Warring States) Period to the peaceful Edo Period. The mine is now closed, but it is still possible to explore inside its impressive interior. Although silver had been produced in Ikuno since around the year 800, full-scale mining did not begin until 1542, when silver nuggets were dug out of the ground. Later, the largest vein of native silver in all of Japan was discovered here, and mining began in earnest under the direct control of Nobunaga Oda and Hideyoshi Toyotomi. In 1600, Ieyasu Tokugawa—the founder of the Tokugawa shogunate—appointed a magistrate to the Tajima gold and silver mines, assigned protected status to the Ikuno Mine, and made it a key pillar of the government's finances. Production peaked during the reign of Yoshimune, the 8th shogun of the Tokugawa dynasty. Records show that at this time Ikuno was producing 562 kg of silver per month. In 1868, it became the first silver mine in Japan to come under the direct control of the Meiji government. A French engineer was invited to introduce new technologies from abroad, becoming the first ""hired foreigner"" in Japan. The mine thus played a role in modernizing the nation. After temporarily becoming the property of the imperial family, the mine was sold to a private company. It continued to support the Japanese economy until it eventually closed in 1973, bringing an end to its long history. Today, the area around the mine bears numerous traces of its illustrious past.