Sado Island lies off the north-western coast of Japan. While not very productive in terms of farming, it boasts some of Japan's richest deposits of gold and silver. Its isolated location makes it easily defensible and a good strategic position. Due to its remoteness from Kyoto and Edo, it was a frequent place of exile for politically inconvenient public figures, among them the Emperor Juntoku and the founder of Nichiren Buddhism, Daishonin.