Tonbai walls are made of discarded fire bricks (tonbai) that were used to compose the climbing kiln for Arita Ware, together with pieces of disposable firing tools, and porcelain pieces, all cemented with red clay. It is said that in the Edo period, potters built high tonbai walls in order that the secret of pottery making could not be seen from the outside. Once the extension of the walls reached 875 meters in total, but as they were made of clay and fragile, most of them have broken down now. 80% of the walls were built in Kami-Arita area, especially along the street from the big gingko tree in Izumiyama to Arita Ceramic Art Museum in Odaru.