The Imperial Palace East Gardens (Kokyo Higashi Gyoen)

This is a beautiful Japanese style garden within the castle walls, in which you will find large lawns, a pond with gorgeous and huge fish, many cherry trees, which blossom you just must see if you are in Japan in March or early April.
The gardens are open from March to October 9:00 - 16:00 and from November to February 9:00-3:30. (You must enter the gardens at least half an hour before closing time)

The gardens are closed on the following days: Every Monday and Friday (open on National Holiday except the Emperor's Birthday, December23) From 28 December to 3 January

The visit in Imperial Palace East Gardens is free of charge and you can enter them from Ote-mon Gate, Hirakawa-mon Gate and Kitahanebashi-mon Gate.