I just input "Penny Pack Park, Philadelphia, PA" and it came right up on the park where the picnic is.
Just to confirm, the park is on the Delaware River so turn off of State Rd. down Pennypack Path,which is about 1/2 mile north of Cottman Ave. but south of Rhawn St; you'll pass under I-95 and pass some kind of detention center, keep going and follow it around to the park and you can't miss the spot.
This is looking north on State Rd. right where you turn toward the park. Where that pickup truck is, turn down that road to the right, go under 95 and keep going.