Center City Philadelphia 費城!
(Not far from Rittenhouse)
But, I KNEW it was the right place when I saw the gate! There's a special gate, and at certain times the gates are closed. You never really know why, because I've been around during various parts of the day or night when it was open or closed.
I wish I had sought out this place earlier because they have a live music series of musicians playing music inside the small park. I had JUST missed it when I got there.
Maybe I will try again to catch it tomorrow.