Sounds like a Magic Tree House book, right? Mummies at the museum was our main purpose for a trip to the Baltimore Walters Art Museum. They had a whole section on Ancient Egypt which we wandered through and read some info. It was a great review since most of our ancient history keeps coming back to Egypt so far. (We haven't even begun Roman or Greek history yet.) I enjoyed myself and they had a good time too.
We hopped over to the Chamber of Wonders which was recommended by the staff for the kids. They enjoyed the butterflies and the magnifying glasses.
Drewy was the best museum baby ever. He uncharacteristically didn't make a peep and stayed in the stroller the whole time.