The Kennedy Center for the Performing Arts can be considered the headquarters of stage performances in Washington, or even the whole country for that matter! The entertainment facility is immense as it sprawls out over 17 acres, overlooks the Potomac River and features six theaters that are always staging various productions like plays, operas, ballets and lots more. There are tours of the facility itself, as well as several exhibits and even an excellent concession area.
For a high-flying afternoon with the whole family, head out to the National Air and Space Museum. Part of the Smithsonian group of museums, this venue presents several life-size exhibits and attractions that only make them all the more dramatic. This is the Smithsonian's most visited museum largely due to the dozens of aircraft that are on display that include Lindbergh's aircraft to the Wright Brothers' Flyer and lots more.
The Washington and Old Dominion Trail (W&OD or "Wad") is an excellent recreation trail that runs through the Northern Virginia counties. The 45-mile trail is completely paved with nine foot wide asphalt and has a yellow painted center line. To run the whole trail and back means you're looking at a 90-mile trek, but it can be done over the course of two days thanks to the hotels and bed and breakfasts along the trail. The only real complaint from bikers is that there's much traffic most of the time due to the Wad's immense popularity.