One day, if you don't mind driving less than 30 miles, why not take a trip to Annapolis? It's a great historic Capital and once you park your car, you can wander the streets, visit sights, shop, eat, take a boat ride, visit the Naval Academy, and just enjoy the scenic waterfront.
I would urge you to check out the site, and also use it to find the parking garage next to the visitors center. The parking is quite inexpensive in the garages, and is much easier than on street or meter parking which is limited to 2 hours and you MUST move your car after that time. At the visitor's center you can pick up a walking tour map which will guide you through the cobblestone streets and showcase the many historic homes and people who lived there. I don't think you will be disappointed.