While visiting Philadelphia with kids in tow, you might be unsure of how to fill your day. Not to worry: There's enough to do in the City of Brotherly Love to keep youngsters and adults happily occupied. Though I have no children of my own, my niece and nephew visit me in Philly every summer. Ages 5 and 7, these kids have given me a run for my money when it comes to keeping them entertained. From them, I've learned which activities really appeal to young children.