Also in Baltimore you have the National Aquarium in the Inner Harbor area (which is the touristy area of town), the Ravens, and the B&O Railroad Museum. If you like architecture or churches, the old Basilica, the first Catholic cathedral in the U.S., is a rare cathedral built in the Federal style. There is a Babe Ruth museum somewhere near Camden, but I would not expect too much from it.

There are a few nightlife districts. Federal Hill and Fells Point are probably the biggest concentrations of bars/restaurants, and both are walking distance from the Inner Harbor, as is Little Italy. A little farther uptown is Mount Vernon, which is a little older/upscale.

Also, be aware that much of Baltimore is quite unsafe for a visitor after dark. It may not attract headlines like Detroit or have a reputation like New Orleans, but Baltimore has one of the highest violent crime rates in the country.