Timber from Ishikawa
In general, castles were designed to be very strong and so many big posts and thick boards were used in their contruction. In the Edo period, Kaga Province had a tree preservation law called "Shichiboku-no-sei" which forbade cutting down seven important kinds of trees, such as cedar, Japanese cypress, and zelkova. We used 40 or 50 times as much wood as we would have for an ordinary house, and 72 percent of the timber came from Ishikawa Prefecture.