Hellobee Boards

Please touch museum is great, it's not in center city so it can be a pain to get to without a car. The 38 and 40 buses stop pretty close and there is a paid lot and free street parking right around it. The Franklin institute is also great but probably leans older. Independence hall and the liberty bell are free you just have to stand in line for tickets, if you wanted to try it will your kiddos. The zoo is the oldest in the country I believe and is pretty nice, although some parts show its age. The Camden aquarium is across the river and is really nice. I totally recomend reading terminal market for lunch, it's crazy and chaotic but there are a million different stalls offering everything from falafel to crepes to amish food and everything in between.

@LadyDi: glad to help. I have lived and still work in philly and always happy to help people enjoy the city.

Academy of Natural Sciences is great and right downtown. Love the Please Touch Museum, and also in Fairmount Park (besides the Zoo) and less well known are Smith Playground which has a huge outdoor wooden slide, and the Shofuso Japanese House, lovely during cherry blossom season and has a koi pond. The Aquarium is fine and you can drive there or take a ferry from the Philadelphia side of the River. The historical Big Bus tours can be fun if it's nice out, and you could always do the Phlash shuttle that is hop on/hop off and stops at a bunch of different locations. Walking along the Schulykill (Boathouse row) and then the sculpture garden at the Museum is a nice day. There's also currently Candytopia and Wonderspaces exhibits going on near downtown which could be cool.