A great way to get views of the city while on a nice walk along the water. Connects lots of great spots! Some of our favorite parts are the boardwalk between South Street and Walnut and the area between the Art Museum and the Fairmount Water Works (both worth a visit in themselves)!
Philly has LOTS of Museums and they're all worth a visit. We especially love the Art Museum, the Barnes, and PAFA for more traditional art museums, but if you want something truly unique and fascinating, check out Eastern State... a stabilized ruin you can explore freely while also seeing contemporary art installations and learning about the history of the American prison system.
Your one-stop shop for all Philly history: Independence Hall, the Liberty Bell, the Constitution Center. It's all worth doing, but here are some slightly off the beaten path favorites: Elfreth's Alley (the oldest residential street in America) and the Ben Franklin House (with a very cool outside space before you have to go in the Museum).
The classic Philly science center, great for kids and adults alike. Don't miss old standbys like the giant walk-through heart and the Ben Franklin-inspired electricity exhibit. The current special show was created for the 100-year celebration of The Walt Disney Company and immerses you in your favorite Disney stories.