Shimōsa Plateau
The Shimōsa Plateau has supported a population since ancient times, as evidenced by the large concentration of Jōmon period "kaizuka" or shell middens across the plateau. The plateau was historically located in Shimōsa Province, after which it was named, and was a productive agricultural area prior to the industrialization of Japan. The area served to produce rice and vegetables as early as the Nara period. Ranches on the Shimōsa Plateau flatlands were developed to raise horses. Additionally, the network of rivers and canals provided for the inland transport of marine products from the Pacific Ocean to Edo. During the Edo period the Shimōsa Plateau saw large-scale development of new rice paddies by the Tokugawa shogunate, as well as the further development of horse ranches, specifically the Kogane and Sakura ranches to supply horses to the shogunate. The inland water routes from Chōshi were developed to supply rice, marine products, and vegetables directly to the capital at Edo.