Sanjo City in Niigata Prefecture has been known for its blacksmiths since the 17th century. At that time, the area was susceptible to flooding, often resulting in famine. Farmers were encouraged to forge nails as a sideline to their agriculture, to help them survive in lean years. Sanjo became an important production center for wakugi, the Japanese nails used in building shrines, temples and other wooden structures. That tradition continues to this day, with one local artisan producing nails for the periodic rebuilding of the Grand Shrine of Ise, in Mie Prefecture.