I took a half-day trip in late autumn to Musashi-Koganei Park, a very beautiful and peaceful place. The Tamagawa Jousui (water purification system for Tokyo) runs through one side of this park. Some people were running, others cycling, playing, and walking their dogs. And you can also find a free museum inside, the "Edo Tokyo Open Air Architectural Museum" Wow it's like a time-trip! Some buildings are from the Meiji Era (1868-1912), some from the Taisho Era (1912-1926), and even some are from the Edo Era (1603-1867)...A very rare experience, for sure.
Find out more about Edo-Tokyo Open Air Architectural Museum.