Among mountains of Shimane prefecture, "Tatara iron making" which is an old iron making method has been actively carried out. This method is to produce iron by putting iron sand taken from a river or mountain together with charcoal in a furnace made of clay and continuing to burn for three days and three nights. Only this method can produce "Tamahagane" steel which is a raw material for the Japanese sword. Currently the steel making is only done once a year, but the former site of the iron making 'Sannai' is still the only one remaining as “Sugaya Tatara Sannai”.