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.