For the last five years my daughter (now about to turn
11) and I have done a yearly "Dad Camp" at the end of the summer. We do all kinds of things, some of which are geeky.
The Maryland Zoo in Baltimore is a pretty mediocre Zoo, unfortunately. They have a few interesting animals, and a small train to ride. The coolest thing at the Maryland Zoo, however, is probably the Penguin Cam.
The National Aquarium in Baltimore is more than just some fish in tanks. The most recent addition includes a large Australian exhibit. There is a rain forest on the top floor, and the large dolphin exhibit includes a view from below. The Aquarium is part of Baltimore’s Inner Harbor, where there are other geeky exhibits, including the last survivor of Pearl Harbor, USCG Cutter Taney, and a WWII
"pig boat" (attack submarine) the USS Torsk.
At the other corner of the Inner Harbor is the Maryland
Science Center, which includes many kid-friendly exhibits and an IMAX Theater. Between some IMAX shows you can see a three-minute short, "Hubble: Galaxies Across Space & Time", a journey across 9 billion years of cosmic history.
Port Discovery is also nearby, though we’ve never been there. It seems aimed at younger kids.
A bit further away is the Baltimore Museum of Industry (shown), which is housed in a former cannery. The history of child labor in Maryland, and the odd distinctions between the jobs reserved for white workers versus those only fit for black workers is frankly bizarre. The company store (with predictable economics) and the printshop are also great exhibits.
A little further south is Fort McHenry, where the actual
"Star-Spangled Banner" flew during the bombardment about which
Francis Scott Key was writing. This is one place that it’s best to go with a school group, which gets you a flag change, a ranger to talk about the fort, and for some groups, and a chance to load
(but not fire, darnit) a cannon.