 Also Bungo Topography tells about Akayusen (Chinoike Jigoku).It is reported that in the Kamakura period Ōtomo Yoriyasu established some sanatoria in Beppu, Kannawa and Hamawaki to cure samurai wounded in the war against the Mongolian Army.From the Meiji period onward Beppu Onsen made great progress with the boring technique of Kazusa, in which more than 1000 wells were completed by the end of Meiji.