The central province of the Kaiu is the most fertile area of the Crab lands, and has many important mines. The jade mines have begun to run out in recent generations, but the land still produces over half the rice grown within the Crab territories. While an impressive amount, it is never enough to feed the hungry legions on the wall. There is a great focus in this province on the purity of nature, and the importance of maintaining that purity. A great deal of woodwork is done here, and samurai from this province are taught to study trees and wood from a young age.