Eastern Penetentiary is in the Art Museum area, out the Ben Franklin parkway away from Center City. However, there is a good restaurant called "Jack's Firehouse" across the street from it. They have a website. It is in an old firehouse.
And of course, you must get a cheese steak while you are here. Jiim's Steaks on South Street is good, but there are probably some good ones in Reading Terminal Market as well.