Even though this was mainly an exploratory trip, I can recommend that you check out the Benjamin Franklin Bridge. You can walk all the way across on either side of the bridge, though the south side seemed more scenic. You can get on where the bridge intersects with 5th Street on the Philadelphia side.
The Bourse is worth a quick stop, even if you aren't looking for fast food. It's a former stock exchange floor with plenty of character remaining in its atrium. Oddly enough, there's also a Mexican consulate located on the third floor. If only it were a British consulate, then the irony would be complete.
Granted, we barely scratched the surface by mainly staying in the