Visiting Washington DC
This section could go on and on and on. There are a ton of tourist sites if you are visiting DC, but people log in and ask. Everyone has their preferences/favorites, so here is some basic information and links.
Some sites in the city require timed tickets if you want to do more than just see the site from the outside and most, if not all, now have options to purchase tickets in advance online if you want timed tickets (for example, the US Capitol, Ford's Theater). The ticket itself is free, you are paying the service fees to buy it in advance. There are likely some sites that explain this better than I can typing quickly here, but for example, if you want a tour of Ford's Theater or to go in and up the Washington Monument, you need a ticket. If you just want to walk around the outside, no ticket needed.
Also, additional timed tickets are handed out same day on a first come first serve basis. Some of the sites require all in your party to be there to get the tickets; some let one person pick up a few tickets. If you have an interest in a site,
check the Check the National Park Service website in advance to see what your options are.
Washington Tourism Information Sites
Destination DC
and
Downtown DC
White House, US Capitol, National Mall
White House, President's Park
U.S. Capitol
National Mall and Memorial Parks
(Washington Monument, Lincoln Memorial, Vietnam Veterans, Korean, WWII, Jefferson Memorial, FDR Memorial, etc.)
Museums/Other Tourist Sites
not an exhaustive list, there is so much to see in the area
Smithsonian museums
Museum of Natural History
Museum of American History
National Portrait Gallery and American Art Museum (immediately across from Verizon Center)
Air and Space Museum (one on the Mall, newer/bigger one Udvar-Hazy Center out by Dulles Airport; only cost is for parking at U-H near Dulles)
and more, see the link above
National Archives including the permanent exhibit of the Constitution, Bill of Rights, and the Declaration of Independence.
National Gallery of Art
Smithsonian's National Zoo
U.S. Botanic Garden
Ford's Theater
Holocaust Memorial Museum
Other Museums (note: admittance fee, near the Verizon Center)
Newseum
International Spy Museum
More in the Area:
More information/National Park Service links -
see this post at HFBs
Great Falls, MD/VA
Arlington National Cemetery
Mt Vernon (in VA)
Old Town Alexandria (in VA)