Visit recommendations/suggestions on where to stay?

Hi, my boyfriend and I are traveling for a business trip towards the end of the month and have never been to Philadelphia, so we're looking for some advice on where to stay for a couple extra nights to check out the city. We're doing some of our own research (Google lol) but I'd rather hear from some locals.

We're super into checking out museums/history/arts, but not into bars or sports in general. Both in our 30s, we're open-minded and laid back, and were talking about the Mutter Museum for sure, we're both into medical history, but what else would be recommended?

Any thoughts/advice would be hella appreciated!!

Thank you!!!