Large indoor stadium structure built during the mid-1960s in downtown Tokyo specifically for the practice and demonstration of Japanese martial arts. Events such as music concerts are also held there. It is the site of the annual All-Japan Aikido Demonstration sponsored by the AIKIKAI HOMBU DOJO. Nippon Budokan, 2-3 Kitanomarukoen, Chiyoda-ku, Tokyo 102 Japan (03)216-5100.