As a native Philadelphian (and a mom of 3), I have to be honest, traveling with children really isn't stress free but there is PLENTY for kids (and adults) to do. Philadelphia has gotten a really bad rap over the years (booing their own sports teams, etc), but if you're going to travel there (especially with children), PLEASE do your homework & find out about the sights before you even leave home.
Don't worry about driving in the traffic "downtown" (compared to New York or Washington, Philly's traffic is a breeze) or you can even the public transportation system. With SEPTA, (Philly's public transportation system) you can pretty much get to wherever you need to go. The following places sure shouldn't be missed.
1. Franklin's Court. Here you can see the outline of Benjamin Franklin's house, watch a short film on his life, and see an exhibit on some of Ben Franklin's inventions. And it's FREE!
2. Please Touch Museum. This museum lets the kids interact with the exhibits. Let them watch the Please Touch Playhouse (with includes music and puppets) and let them ride the carousel. This museum is great if you're traveling with toddlers. Cost is only $15 per person. Children under 1 year old are free.
3. Philadelphia Zoo, this is the country's first zoo and home to tigers, cheetahs, giraffes, polar bears, gorillas, and so much more. Adult tickets are $17.95 and children 2-11 are $14.95. Discounts apply for visiting in December-February.
4. Philadelphia Art Museum. All kids want to run up the steps like Rocky Balboa. However, most adults don't even want to think about it! But this museum offers everything from medieval to modern day art. And Sundays is pay what you want day.
5. Geno's Steaks on Passyunk Avenue (pronounced pass-SHUNK). It's worth the standing in line for a few minutes to order a cheesesteak (wit means with onions) or a roast pork and most kids think it's cool to eat outside at one of their tables. Stay there long enough and chances are the whole city will walk by.
6. New Jersey Aquarium. Ok, I know it's on the Jersey side, but during the summer you can take the ferry across from Penn's Landing to the Aquarium or just take 15 minute drive over the Ben Franklin Bridge to Camden. For $18.95 per adult and $14.95 per child, you can see sharks, rays, fish, crab, and squid. You can even pet baby sharks in one of the tanks!
7. Franklin Institute Science Museum. Kids can walk through a giant beating heart and learn about electricity. Don't miss the Fels Planetarium for a view of the cosmos. Take a trip to India, the Alps, or the Grand Canyon in the IMAX Theater. This is truly one of the coolest kid/adult museums ever!
When you know you're going to travel with children, it helps if you're informed to know what there is to do for them. Thus, reducing your stress (and theirs) in the city of Brotherly Love!