If your in D.C, there are a zillion things to do but also a zillion tourists.
 The Zoo is nice early in the morning.  If your in Mass. for awhile go to
Sturbridge Village and Hancock Shaker Village.
 
There is a good website called "road side america".  I'm not sure of the
address, it could be ROADSIDEAMERICA.COM.  There you will find things like
Santa's Land in Putney Vt. and Nash Dino Land in Hadley, Ma.
 
Ned Heite mentioned several places in Del, Pa., southern NJ but neglected
southern NJ's most interesting cultural experience.  If you pass by that why
on a Saturday or Tuesday morning Cow Towns the place to be.  Look for Herbie,
the pickled sausage king of the Mid-Atlantic.
 
As for Boston, the Black Rose serves a fine pint of Guiness.
 
jo Balicki
JMA