One of my favorite park in Tokyo is Yoyogi Park. Located right in the heart of Tokyo. Amid the concrete jungle of skyscrapers Tokyo megapolitan, there was a board green lush forest... Yoyogi Park.
Lush green Yoyogi Park
It's a wide scale park, one side of Yoyogi Park can be accessed from Yoyogi station, and the other side can be accessed from Harajuku station. I prefer the access from Harajuku station, because once we exit the station, directly jump into the middle of Tokyo young generation gathering center.
Just a step from Harajuku station is the entrance to Yoyogi Park, near Meiji Shrine. This kind of contrast makes me love Tokyo! Look to the left, there is a hype shopping centers, full of funky teenagers, ...and look to the right, there is a lust green deep forest with some kimono clad adults head up to the Meiji Shrine.