The Upper Northwest corner of D.C. is predominantly residential and in many places practically suburban. There are several good reasons, however, to visit the leafy streets, including the National Zoo and National Cathedral.
If the weather is fine, spend an afternoon strolling through Hillwood Gardens or tromping through Rock Creek Park's many acres. You'll have to travel some distance to see multiple attractions in one day, but many sights are accessible on foot from local Metro stops.