Iwami Ginzan Silver Mine

This Shimane mine opened in the early 16th century and stayed in business for nearly 400 years. UNESCO credits its large silver output in the 16th and early 17th centuries with driving trade and cultural exchange between Japan, East Asia and Europe. Travel guides often say it produced about a third of the world's silver, though estimates of its share vary. Today it is mostly forest, with moss-covered stone ruins. Walk 30 to 45 minutes up the valley from the Omori bus stop to the Ryugenji Mabu, a 273-meter tunnel and the only one of more than 600 shafts open to explore freely. Omori town has old residences, shrines and the former government office. Buses link Omori with JR Oda-shi Station hourly, so allow a full day.