Traditional DC food spots include Ben's Chili Bowl on U Street (there's also one in Nats Park), Old Ebbitt Grill near the White House, and Martin's Tavern in Georgetown (where JFK proposed to Jackie). The DC food scene has really grown and you can get some very fine dining from places such as Komi, Rose's Luxury, and Pineapple & Pearls. Some off the beaten path tourist sites include Lincoln's Cottage at the Old Soldier's home, the National Arboretum, and the Titanic Memorial. I second the Udvar-Hazy center out by Dulles. Bit of a drive but so much bigger than the Air and Space museum on the mall. Chinatown is pretty much two or three blocks and most of the native Chinese residents have moved away. Now all you see are Citibank signs with Chinese letters underneath. You can skip it unless you happen to be at the National Portrait Gallery which is right on the edge of Chinatown. Close-ish to Nats Park is the new Wharf Marina which they are trying to turn into a new spot for restaurants/concerts. It is very nice to walk around but kind of feels sterile since all of the buildings are so new. Old Town Alexandria is a very nice place to walk around as well and has some good food. Lots of cobble stone streets. Just FYI the Metro has been having issues with delays recently. Please be patient as our system is going through a lot of repairs and maintenance this summer. I would budget in extra time in case there is a wait between trains. You can download apps or go on the Metro website to get somewhat accurate info on when the next train is scheduled to arrive.