The Iwami Ginzan (石見銀山) was an underground silver mine in the city of Ōda, in Shimane Prefecture on the main island of Honshu, Japan. It was the largest silver mine in Japanese history. It was active for almost four hundred years, from its discovery in 1526 to its closing in 1923.
The mines, mining structures, and surrounding cultural landscape — listed as the "Iwami Ginzan Silver Mine and its Cultural Landscape" — became a UNESCO World Heritage Site in 2007.
The mine was discovered and developed in 1526 by Kamiya Jutei, a Japanese merchant. Jutei later introduced a Korean style of silver mining that would become the Haifukiho Method. The mine reached its peak production in the early 1600s, with approximately 38 tons of silver a year while Japan produced about 200 tons of silver a year which was then one third of the world's production.
Silver from the mine was used widely for coins in Japan. It was contested fiercely by warlords until the Tokugawa Shogunate won control of it in 1600 as a result of the Battle of Sekigahara in 1600. It was later secured by fences and barricaded by pine trees. Yamabuki Castle was built in the center of the mining complex.
Silver production from the mine fell in the 19th century, as it had trouble competing with mines elsewhere in the world. Mining for other minerals, such as copper, then replaced silver as the predominant material produced from the mountain. The mine was eventually closed in 1923.