The Barnes mostly if you enjoy 20th C painting. Good Mickalene Thomas (contemporary) exhibit up there now. Interesting history and building.
Pennsylvania Academy of Fine Arts has a fun Frank Furness building right near city hall but it’s closed for renovations. Go back again.
Macy’s across from City Hall, used to be locally owned Wannamakers. They have the largest working pipe organ in the world and regular music performances, especially in the holiday season. The store itself no longer has the vintage charm it once did, but catching a mini concert is fun.
Third Street Gallery is an artists cooperative and has some good shows.
Shane Candies at first and market streets is 19th C style redone.
The Liberty Bell a block north of I dependence Hall if you’re interested. Indépendance Hall too. The cluster of buildings that include what used to be Franklin’s printing shop is I retesting and rarely crowded. Sadly I see they are now only open Friday -Sunday.
https://www.nps.gov/inde/planyourvisit/printingoffice.htm
I think there’s a colonial post office in the court from where you can have your letters and post cards ( c’mon snail mail is the best) hand cancelled.