One place that I liked to visit is the Port of Wilmington, four miles east of the city. It even has separate exit ramps on I-95. I never saw much freight activity in Philadelphia. By contrast, Wilmington always seemed busy and schedules are on the internet. At various times, industrial equipment, canned food, and automobiles took off from here. It was exciting to watch the packaging and the ships leave port. I always kept popcorn, fed it to the egrets, and watched them swoon down gracefully on the ramp.
In the wake of 9/11, this now may closed to anyone just driving in there. My guess is that the greater number in ships in Wilmington versus Philadelphia stems from deeper water, less traffic, and the absence of any income tax in the Diamond State. These easily offsets the four mile distance from I-95.