Shinjuku Central Park is a well known one and it is surrounded by skyscrapers, but this one doesn't have them.
Any hints?
Now I managed to spot it. The park is actually Makuhari Kaihin Park (幕張海浜公園) in Chiba, not in Tokyo (that's why I was not aware of it).
And yes it is on reclaimed land, the homepage of the park in fact mentions liquefaction.
Shinjuku Central Park is a well known one and it is surrounded by skyscrapers, but this one doesn't have them.
Any hints?