Having a kid changes your idea of fun. Not that you can't still enjoy the stuff you enjoyed when you were unencumbered by parental responsibility (though you should probably lay off the binge drinking, if you're still doing that). But what you think of as a fun day must be thereafter tempered by what your progeny will think is a fun day-at least until they fall asleep. At which point you'll probably want to go to sleep too, as you'll be a lot more tired, but we digress. Baltimore offers plenty of opportunities to keep the tykes amused, a good thing all the way around, and here are a few.
Attractions How many times during the average museum visit do you end up whisper-shouting to your children not to touch anything? Many, many times, right? Good thing that's not an issue at the Maryland Science Center (601 Light St.,  685-2370, mdsci.org, $11.95-$18.95). MSC is all about touching, trying, manipulating, and observing thanks to three floors of designed-with-kids-in-mind hands-on science exhibits, from fossil prospecting to Newtonian physics experiments, from constructing space exploration equipment to lying on a bed of nails. Also, fart sounds. Touring exhibits make multiple visits pay off, as do the affordable admission and membership rates.
You can't touch most of the thousands of creatures on display at the National Aquarium (501 E. Pratt St.,  576-3800, aqua.org, $19.95-$29.95), but it isn't the granddaddy of Charm City kid attractions for nothing. Exotic fish and other sea life abound, spanning the seven seas as well as fresh water habitats (the Amazon) and deserts (the Australia exhibit), plus the visit-capping dolphin show. Protip: Buy your tickets online to avoid long waits during prime tourist season.
We're not sure there are thousands of creatures on display at the Maryland Zoo (Druid Hill Park,  396-7102, marylandzoo.org, $10.50-$16.50)-maybe if you count the squirrels-but the hundreds on view at this venerable, rebounding institution make a stroll along the leafy hills of Druid Hill Park all the more pleasant.
When it's raining, our go-to has long been Port Discovery (35 Market Place,  727-8120, portdiscovery.org, $13.95), a play-centric children's museum dominated by a towering multi-story climbing structure in the central atrium. It's tons of fun when it isn't raining, as well.
Generally, we are not those parents who tour our kids around historic sites. That said, we love Fort McHenry National Monument and Historic Shrine (2400 E. Fort Ave.,  962-4290, nps.gov/fomc), which is not only the object of the 1812 naval bombardment that inspired Francis Scott Key to write "The Star-Spangled Banner," it's also a super cool fort with ramparts (i.e. broad walls) for dashing about. Lots more fun than those Civil War battlefields.
Many of the city's more grown-up museums and cultural attractions have numerous kid-friendly exhibits and an active event and program schedule for wee ones. For more info, see the American Visionary Art Museum, Baltimore Museum of Art, Walters Museum of Art, Reginald F. Lewis Museum of Maryland African-American History and Culture, the B&O Railroad Museum, and the Baltimore Streetcar Museum in Tourist Attractions (page 14) and/or The Arts Scene (page 20).
Parks and Playgrounds You will hear people in Baltimore talk about the (mostly) friendly rivalry between the city's east side and west side. Likewise, you will occasionally hear people debate the merits of East Baltimore's Patterson Park (pattersonpark.com) and West Baltimore's Druid Hill Park (druidhillpark.org). It's sort of six of one, really-they're both enormous city parks featuring sports fields, tennis courts, walking/running trails, pools, and other amenities. We love them both (though Druid Hill's clearly the best-west side!).
The historic Federal Hill neighborhood isn't just good for bars and miserable parking. It also boasts Historic Federal Hill Park, with its playground and ample grassy bulk and incomparable view of downtown and the Inner Harbor.
That said, serious players know that Our Playground at Stadium Place (900 E. 33rd St., stadiumplayground.org) is the spot. Convenient to the Charles Village/Johns Hopkins area, it covers a football-field-ish area with community-constructed climbing and hiding and playing options. Also, plenty of parking.
If you're looking for something a little less citified, the surrounding 'burbs offer plenty of options just a few miles outside the I-695 beltway. Irvine Nature Center (11201 Garrison Forest Road, Owings Mills,  738-9200, explorenature.org) offers cool, hands-on ecological exhibits inside its mod center and a newly expanded outdoor play/learning area (though the latter is for center members only), plus numerous nature trails.
Oregon Ridge Park (13555 Beaver Dam Road, Cockeysville,  887-1815, baltimorecountymd.gov) boasts a nature center as well, albeit a more old-school version, but perhaps the biggest attractions are the trails, swimming beach, and playground.
Speaking of playgrounds, one of the best in the area is the Scrap Tire Playground (Hilton Area of Patapsco Valley State Park, Ellicott City,  461-5005, dnr.state.md.us/publiclands/central/patapsco.asp), tucked away in the heart of a state park to the west of the beltway. You guessed it: an entire playground constructed entirely from scrap tires (including behemoth heavy-equipment tires). And the rest of Patapsco Valley State Park offers plenty of other fun kid-friendly outdoor activities too.
Toy Stores Sometimes, a kid just wants something new to play with, especially if grandma is buying. Though on the small side, Barston's Child's Play (Village of Cross Keys, 86 Village Square,  435-0804, barstonschildsplay.com) is one of the best all-arounders, filling its space in an upscale shopping area with fun items spanning genders, ages, and interests.
Nearby Shananigans Toy Shop (Wyndhurst Village, 5004-B Lawndale Ave.,  532-8384, shananiganstoyshop.com; second location in Woodlawn) covers much of the same ground but brings a fun-loving, plaything-connoisseur's eye to its stock.