Just south along MD-5 is Point Lookout State Park, which is the southern tip of Southern Maryland, at the confluence of the Potomac River and the Chesapeake Bay. It's a worthwhile and quick excursion for the watery views, an old lighthouse, and some the remains of some Civil War fortifications.
Solomons Island is a small historic resort town, just across the Patuxent River on MD-4.
Past Solomons along MD-4 is Calvert Cliffs State Park, which is a nice place for hiking, or beach-combing for shark teeth, in addition to admiring the cliffs themselves. A little further north from Calvert Cliffs is a nice sandy beach at Flag Ponds Nature Park.