Kokyo Gaien National Garden (or Kokyogaien National Gardens) is a extensive park surrounded by an abundance of nature that makes people forget they are in the center of a big city. With 2,000 well spaced Japanese Black Pines, moats, bridges, walls, gates and guardhouses of the Imperial Palace, it was once part of historical Edo Castle. It's peaceful and tranquil. Enjoy !
You can rent a bike in order to see all the park's corners, or just walk around and easily spend a couple of hours. The garden sits just a five-minute walk from Hibiya metro station. Enjoy your next trip to Japan.