Kodokan, or the Kodokan Institute, is the headquarters of the worldwide judo community.
Literally, kō means "to lecture", dō means "way," and kan is "a public building" together translating as "a place for the study of the way."
The Kodokan was founded in 1882 by Kanō Jigorō, the founder of judo, and is now an eight-story building in Tokyo.
