Mori Art Museum (森美術館) is an art museum, located at 六本木6-10-1 (六本木ヒルズ森タワー 53F), 港区, 東京都, 106-6161, 日本. They can be contacted via phone at +81 3-5777-8600, visit their website www.mori.art.museum for more detailed information.
you can always find some interesting exhibitions and the view is amazing (way better than Tokyo Tower..!)
Has the best view of the city (in addition to the art). Go on a clear day.