DN Tower 21[note 1] is an office building in Tokyo, Japan.
It includes the former Dai-Ichi Seimei Building, in which Douglas MacArthur had his headquarters during the occupation of Japan following World War II.
The shorter building was designed by the Japanese architect WATANABE Jin and MATSUMOTO Yosaku.
The taller 21-story building (at 99.8 metres in height) began construction in 1988 and was completed in 1993, and was designed by the Irish-American architect Kevin Roche.
The building still serves as headquarters for both the Norinchukin Bank and Dai-ichi Life.