I fly there at the water works and boathouse all the time and sometimes I would see police helicopters and security guards at the park but they are not saying anything to me to indicate that it's illegal to fly there, so I'm guessing it's ok to fly there. The only no fly zone I know in Philly is flying over stadiums even if there is no ongoing game we are not allowed to fly over stadiums for some reason. Here's couple pictures from the water works.
@rccrazy30 - Nice. I'm just looking for people and locations to fly with for day trips or whatever. I have an Inspire and 3DR Solo. Looking to grab a mavic once there are real users with them for a while because I travel a lot and even my Solo is too big to be lugging around an airport or wherever.