It's hard to believe there's people in this city who haven't spent a day looking at all the wonderful pieces in the Philadelphia Art Meuseum. Spanning many cultures, times, and types of art, it's a great place to spend a Sunday (with discounted admission, too) and take in the sights. They have something for everyone. While the commissary is overpriced (what Center City eatery isnt?), you can just grab a bite to eat before or after. Hell, it's worth seeing just for the Rocky steps.