If you are sightseeing, chances are you are on the Mall. The National Mall is a unique National Park, filled with an intense concentration of monuments, memorials, museums, and monumental government buildings instantly recognizable to people all over the world. The White House, the US Capitol Building, the Washington Monument, the Lincoln Memorial and Reflecting Pool, the Franklin Delano Roosevelt Memorial, the Vietnam War Memorial, the Korean War Veterans Memorial, the Jefferson Memorial, the National Gallery of Art, the National Air and Space Museum, the National Natural History Museum, and the Holocaust Museum, are just a few of the top national attractions here, all within walking distance of each other. The tourist-designated sights are just half of the attraction, though—to walk down the National Mall is to thread the halls of world power in the modern era. Here powerful politicians and their staffs fill the grand neo-classical buildings of the three branches of US Government, making decisions that reverberate in the remotest corners of the world.
There are multiple maps along the Mall, especially by Metro stops, but the place is so jam-packed with things you'll want to see that you should probably take a map with you to avoid missing highlights obscured by other highlights. For a more detailed and larger map than the Wikivoyage version, print out the official National Mall map . The Mall is larger than it looks, and a walk from the Capitol Building to the Lincoln Memorial or the Tidal Basin will take a while and may wear you down a bit. Plan ahead what you want to see and concentrate your activities in one section of the Mall each day.
The eastern section, home to the majority of the museums, is covered in the National Mall article, as are the western portion of the Mall and the Tidal Basin. Many more museums await just north of the Mall in the East End, ranging from the new, flashy Newseum and International Spy Museum to the time tested National Portrait Gallery, American Art Museum, and the home of the Constitution at the National Archives. The White House is located in the West End along with several excellent smaller museums, and the Capitol Building is on Capitol Hill.
While the Mall has more than enough sights to keep a traveler busy for a while, the city itself has plenty of big attractions for a visitor who wants to leave behind the sandy paths and flocks of tourists and pigeons of the Smithsonian. The National Zoo in Woodley Park is one of the nation's most prestigious, and the nearby National Cathedral is an awe-inspiring mammoth. Dupont Circle is home to much of Embassy Row, an impressive stretch of some 50 foreign-owned historic and modernist mansions along Massachusetts Ave, as well as several brilliant small museums, such as the Phillips Collection, the Textile Museum, and the Woodrow Wilson House. Another attraction that shouldn't be missed is the Library of Congress, which has some of the most beautiful architecture that can be seen in the city.
The historic neighborhood of Georgetown is another great sightseeing destination, full of beautiful old colonial buildings, the 200+ year-old Jesuit campus of Georgetown University, a pleasant waterfront, and the infamous Exorcist steps. By car (i.e., taxi), you can get to some of the capital's more far-flung and less-frequented attractions, like the National Arboretum in the Near Northeast, or the Kenilworth Aquatic Gardens in eastern Anacostia. By taking the Metro red line to Brookland-CUA, you can easily visit the magnificent Catholic Basilica of the National Shrine of the Immaculate Conception, the largest Catholic church in North America.