Not to be confused with Koishikawa Botanical Gardens near Hongo. This is definitely one of the best out of the 9 Metropolitan Cultural Heritage Gardens in Tokyo. And it is designated as a Special Place of Scenic Beauty & Special Historic Asset.
This garden dates back to the early 1600’s and has a lot of Chinese influence reflected in the landscape. It is best to go there during Hanami ~ Cherry Blossom season (late Mar. to early Apr.) & during Fall (late Nov. to early Dec.) to view the stunning fall foliage and I hope, my pictures can lure you there next season.
Keep a couple of hours in hand if you plan on visiting this beautiful park. You can sit on one of the benches & munch on some snacks, onigiris or even dig into your bento box & wash it down with some ocha, while taking in the vibrant and captivating beauty of Mother Nature right in the heart of Tokyo !
This website in English gives details about the park & the other Metropolitan parks in Tokyo ~ http://teien.tokyo-park.or.jp/en/koishikawa/outline.html