Tokyo is home to the Ryōgoku Kokugikan, Japan’s principal indoor arena for professional sumo.
The building stands in the Ryōgoku district of Sumida, an area strongly associated with sumo because many stables and training facilities are nearby. The current arena opened in 1985, replacing an earlier Kokugikan that had occupied the site before World War II.
Ryōgoku Kokugikan usually hosts the January, May, and September grand tournaments. Its location is especially convenient for visitors because it is beside Ryōgoku Station and close to the Sumo Museum.
The other three annual tournaments are held in Osaka, Nagoya, and Fukuoka. Those cities therefore host major tournaments, but Tokyo is the city most closely identified with the Kokugikan itself.