Indoor destinations for spring break? Driving from DC.

[Anonymous]

Our middle school has a late March or early April spring break and it's just too cold on any local beach or river - I"m tired of kayaking in strong winds or shivering on a cold beach. This year I want to do indoor things.

What are some East Coast or nearer-Midwest destinations with a lot to do indoors? I'm thinking museums, festivals, aquariums ... but enough that it's worth a multi-day trip. Kids are too old for children's museums. We were recently in NYC already.

Thanks!

[Anonymous]

Philadelphia will have the most to do. Pittsburgh is another option - good art, good architecture, interesting history. Or you could pretty easily do both in a full week..