The Baltimore Aquarium is one of the best. Tickets are ~$50/person and the aquarium opens at 9am. Bonus points if you send Emily a picture of the pump room!
The Guinness Brewery in Baltimore is the only one in America! While the signature stout is not brewed there, there are many tours and tastings available.
Located on the tip of the south Baltimore peninsula, Fort McHenry played a pivotal role in the war of 1812. It is also where Francis Scott Key wrote the national anthem! If you're a history buff, we recommend checking it out.