There are a number of gardens in the Tokyo area where one can view Japanese water irises (花菖蒲, hanashobu) in bloom. The flowers are usually at their most beautiful in June. Below is a list of some of the best locations to see them.
TOKYO
Nezu Museum, Minato Ward
Koishikawa Korakuen Garden, Bunkyo Ward
Meiji Jingu Inner Garden, Shibuya Ward
Imperial Palace East Garden, Chiyoda Ward
Horikiri Iris Garden & Mizumoto Park, Katsushika Ward
Kiyosumi Garden, Koto Ward
Shobunuma Park, Kita Ayase, Adachi Ward
Shakuji Park, Nerima Ward
Koiwa Iris Garden, Edogawa Ward
Fukiage Iris Garden, Ome
KANAGAWA
Yokosuka Iris Garden, Yokosuka
Sagamihama Park, Sagamihara
Ikutaryokuchi Shobu Pond, Kawasaki
Meigetsuin Temple, Kamakura
Sankeien Garden, Yokohama
CHIBA
Hondoji Temple, Matsudo
Suigo Sawara Aquatic Botanical Garden, Sawara
IBARAKI
Suigo Itako Ayame-en, Itako
SAITAMA
Shobu Joshi Ayame Garden, Kuki