 The earliest inscribed instance of waniguchi written as it is today () is on a bronze example at Ōtakayama Jinja () in Ōgawara, Miyagi Prefecture.With a diameter of , depth of , and weighing some , the long inscription on both sides documents its dedication in Shōō 6 (1293).In recognition of its documentary significance, the waniguchi has been designated an Important Cultural Property.